Improve String matcher handling of case sensitivity

The old implementation of String matchers worked by making a, potentially
lower-cased, copy of both the constructor arg, and the arg to `match` calls.

The new implementation does not make copies, and instead does per-character
lowering if needed. This is a win in **most** cases, with two exceptions:

1) Case-insensitive `Equals` between long strings. The old implementation
   is easy to autovectorize by the compiler, which wins over the extra copy
   with sufficiently long inputs.
2) Case-insensitive `ContainsSubstring` with inputs that trigger the worst
   case complexity of O(m*n) of the naive implementation.

The latter is fixable with some elbow grease by implementing a proper
string search algorithm, but the former is a cost we have to live with.

8 files changed, 48 insertions, 48 deletions

diff --git a/tests/SelfTest/Baselines/compact.sw.approved.txt b/tests/SelfTest/Baselines/compact.sw.approved.txt
index 673c9dd7..09c0bc61 100644
--- a/tests/SelfTest/Baselines/compact.sw.approved.txt
+++ b/tests/SelfTest/Baselines/compact.sw.approved.txt
@@ -631,7 +631,7 @@ Condition.tests.cpp:<line number>: passed: x == Approx( 1.3 ) for: 1.30000000000
 ==
 Approx( 1.30000000000000004 )
 Matchers.tests.cpp:<line number>: passed: testStringForMatching(), Equals( "this string contains 'abc' as a substring" ) for: "this string contains 'abc' as a substring" equals: "this string contains 'abc' as a substring"
-Matchers.tests.cpp:<line number>: passed: testStringForMatching(), Equals( "this string contains 'ABC' as a substring", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" equals: "this string contains 'abc' as a substring" (case insensitive)
+Matchers.tests.cpp:<line number>: passed: testStringForMatching(), Equals( "this string contains 'ABC' as a substring", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" equals: "this string contains 'ABC' as a substring" (case insensitive)
 Matchers.tests.cpp:<line number>: failed: testStringForMatching(), Equals( "this string contains 'ABC' as a substring" ) for: "this string contains 'abc' as a substring" equals: "this string contains 'ABC' as a substring"
 Matchers.tests.cpp:<line number>: failed: testStringForMatching(), Equals( "something else", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" equals: "something else" (case insensitive)
 ToStringGeneral.tests.cpp:<line number>: passed: ::Catch::Detail::stringify(WhatException{}) == "This exception has overridden what() method" for: "This exception has overridden what() method"
@@ -654,11 +654,11 @@ Matchers.tests.cpp:<line number>: passed: throwsDerivedException(), DerivedExcep
 Matchers.tests.cpp:<line number>: passed: throwsDerivedException(), DerivedException, MessageMatches( !StartsWith( "::what" ) ) for: DerivedException::what  matches "not starts with: "::what""
 Matchers.tests.cpp:<line number>: passed: throwsSpecialException( 2 ), SpecialException, MessageMatches( StartsWith( "Special" ) ) for: SpecialException::what  matches "starts with: "Special""
 Exception.tests.cpp:<line number>: passed: thisThrows(), "expected exception" for: "expected exception" equals: "expected exception"
-Exception.tests.cpp:<line number>: passed: thisThrows(), Equals( "expecteD Exception", Catch::CaseSensitive::No ) for: "expected exception" equals: "expected exception" (case insensitive)
+Exception.tests.cpp:<line number>: passed: thisThrows(), Equals( "expecteD Exception", Catch::CaseSensitive::No ) for: "expected exception" equals: "expecteD Exception" (case insensitive)
 Exception.tests.cpp:<line number>: passed: thisThrows(), StartsWith( "expected" ) for: "expected exception" starts with: "expected"
 Exception.tests.cpp:<line number>: passed: thisThrows(), EndsWith( "exception" ) for: "expected exception" ends with: "exception"
 Exception.tests.cpp:<line number>: passed: thisThrows(), ContainsSubstring( "except" ) for: "expected exception" contains: "except"
-Exception.tests.cpp:<line number>: passed: thisThrows(), ContainsSubstring( "exCept", Catch::CaseSensitive::No ) for: "expected exception" contains: "except" (case insensitive)
+Exception.tests.cpp:<line number>: passed: thisThrows(), ContainsSubstring( "exCept", Catch::CaseSensitive::No ) for: "expected exception" contains: "exCept" (case insensitive)
 ToString.tests.cpp:<line number>: passed: tos == tos for: { stringification failed with an exception: "Invalid" }
 ==
 { stringification failed with an exception: "Invalid" }
@@ -1912,11 +1912,11 @@ ToStringGeneral.tests.cpp:<line number>: passed: Catch::Detail::stringify(arr) =
 Matchers.tests.cpp:<line number>: passed: testStringForMatching(), ContainsSubstring( "string" ) for: "this string contains 'abc' as a substring" contains: "string"
 Matchers.tests.cpp:<line number>: passed: testStringForMatching(), ContainsSubstring( "string", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" contains: "string" (case insensitive)
 Matchers.tests.cpp:<line number>: passed: testStringForMatching(), ContainsSubstring( "abc" ) for: "this string contains 'abc' as a substring" contains: "abc"
-Matchers.tests.cpp:<line number>: passed: testStringForMatching(), ContainsSubstring( "aBC", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" contains: "abc" (case insensitive)
+Matchers.tests.cpp:<line number>: passed: testStringForMatching(), ContainsSubstring( "aBC", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" contains: "aBC" (case insensitive)
 Matchers.tests.cpp:<line number>: passed: testStringForMatching(), StartsWith( "this" ) for: "this string contains 'abc' as a substring" starts with: "this"
-Matchers.tests.cpp:<line number>: passed: testStringForMatching(), StartsWith( "THIS", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" starts with: "this" (case insensitive)
+Matchers.tests.cpp:<line number>: passed: testStringForMatching(), StartsWith( "THIS", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" starts with: "THIS" (case insensitive)
 Matchers.tests.cpp:<line number>: passed: testStringForMatching(), EndsWith( "substring" ) for: "this string contains 'abc' as a substring" ends with: "substring"
-Matchers.tests.cpp:<line number>: passed: testStringForMatching(), EndsWith( " SuBsTrInG", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" ends with: " substring" (case insensitive)
+Matchers.tests.cpp:<line number>: passed: testStringForMatching(), EndsWith( " SuBsTrInG", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" ends with: " SuBsTrInG" (case insensitive)
 String.tests.cpp:<line number>: passed: empty.empty() for: true
 String.tests.cpp:<line number>: passed: empty.size() == 0 for: 0 == 0
 String.tests.cpp:<line number>: passed: std::strcmp( empty.data(), "" ) == 0 for: 0 == 0
diff --git a/tests/SelfTest/Baselines/compact.sw.multi.approved.txt b/tests/SelfTest/Baselines/compact.sw.multi.approved.txt
index 73195967..5a2a6e03 100644
--- a/tests/SelfTest/Baselines/compact.sw.multi.approved.txt
+++ b/tests/SelfTest/Baselines/compact.sw.multi.approved.txt
@@ -629,7 +629,7 @@ Condition.tests.cpp:<line number>: passed: x == Approx( 1.3 ) for: 1.30000000000
 ==
 Approx( 1.30000000000000004 )
 Matchers.tests.cpp:<line number>: passed: testStringForMatching(), Equals( "this string contains 'abc' as a substring" ) for: "this string contains 'abc' as a substring" equals: "this string contains 'abc' as a substring"
-Matchers.tests.cpp:<line number>: passed: testStringForMatching(), Equals( "this string contains 'ABC' as a substring", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" equals: "this string contains 'abc' as a substring" (case insensitive)
+Matchers.tests.cpp:<line number>: passed: testStringForMatching(), Equals( "this string contains 'ABC' as a substring", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" equals: "this string contains 'ABC' as a substring" (case insensitive)
 Matchers.tests.cpp:<line number>: failed: testStringForMatching(), Equals( "this string contains 'ABC' as a substring" ) for: "this string contains 'abc' as a substring" equals: "this string contains 'ABC' as a substring"
 Matchers.tests.cpp:<line number>: failed: testStringForMatching(), Equals( "something else", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" equals: "something else" (case insensitive)
 ToStringGeneral.tests.cpp:<line number>: passed: ::Catch::Detail::stringify(WhatException{}) == "This exception has overridden what() method" for: "This exception has overridden what() method"
@@ -652,11 +652,11 @@ Matchers.tests.cpp:<line number>: passed: throwsDerivedException(), DerivedExcep
 Matchers.tests.cpp:<line number>: passed: throwsDerivedException(), DerivedException, MessageMatches( !StartsWith( "::what" ) ) for: DerivedException::what  matches "not starts with: "::what""
 Matchers.tests.cpp:<line number>: passed: throwsSpecialException( 2 ), SpecialException, MessageMatches( StartsWith( "Special" ) ) for: SpecialException::what  matches "starts with: "Special""
 Exception.tests.cpp:<line number>: passed: thisThrows(), "expected exception" for: "expected exception" equals: "expected exception"
-Exception.tests.cpp:<line number>: passed: thisThrows(), Equals( "expecteD Exception", Catch::CaseSensitive::No ) for: "expected exception" equals: "expected exception" (case insensitive)
+Exception.tests.cpp:<line number>: passed: thisThrows(), Equals( "expecteD Exception", Catch::CaseSensitive::No ) for: "expected exception" equals: "expecteD Exception" (case insensitive)
 Exception.tests.cpp:<line number>: passed: thisThrows(), StartsWith( "expected" ) for: "expected exception" starts with: "expected"
 Exception.tests.cpp:<line number>: passed: thisThrows(), EndsWith( "exception" ) for: "expected exception" ends with: "exception"
 Exception.tests.cpp:<line number>: passed: thisThrows(), ContainsSubstring( "except" ) for: "expected exception" contains: "except"
-Exception.tests.cpp:<line number>: passed: thisThrows(), ContainsSubstring( "exCept", Catch::CaseSensitive::No ) for: "expected exception" contains: "except" (case insensitive)
+Exception.tests.cpp:<line number>: passed: thisThrows(), ContainsSubstring( "exCept", Catch::CaseSensitive::No ) for: "expected exception" contains: "exCept" (case insensitive)
 ToString.tests.cpp:<line number>: passed: tos == tos for: { stringification failed with an exception: "Invalid" }
 ==
 { stringification failed with an exception: "Invalid" }
@@ -1905,11 +1905,11 @@ ToStringGeneral.tests.cpp:<line number>: passed: Catch::Detail::stringify(arr) =
 Matchers.tests.cpp:<line number>: passed: testStringForMatching(), ContainsSubstring( "string" ) for: "this string contains 'abc' as a substring" contains: "string"
 Matchers.tests.cpp:<line number>: passed: testStringForMatching(), ContainsSubstring( "string", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" contains: "string" (case insensitive)
 Matchers.tests.cpp:<line number>: passed: testStringForMatching(), ContainsSubstring( "abc" ) for: "this string contains 'abc' as a substring" contains: "abc"
-Matchers.tests.cpp:<line number>: passed: testStringForMatching(), ContainsSubstring( "aBC", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" contains: "abc" (case insensitive)
+Matchers.tests.cpp:<line number>: passed: testStringForMatching(), ContainsSubstring( "aBC", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" contains: "aBC" (case insensitive)
 Matchers.tests.cpp:<line number>: passed: testStringForMatching(), StartsWith( "this" ) for: "this string contains 'abc' as a substring" starts with: "this"
-Matchers.tests.cpp:<line number>: passed: testStringForMatching(), StartsWith( "THIS", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" starts with: "this" (case insensitive)
+Matchers.tests.cpp:<line number>: passed: testStringForMatching(), StartsWith( "THIS", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" starts with: "THIS" (case insensitive)
 Matchers.tests.cpp:<line number>: passed: testStringForMatching(), EndsWith( "substring" ) for: "this string contains 'abc' as a substring" ends with: "substring"
-Matchers.tests.cpp:<line number>: passed: testStringForMatching(), EndsWith( " SuBsTrInG", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" ends with: " substring" (case insensitive)
+Matchers.tests.cpp:<line number>: passed: testStringForMatching(), EndsWith( " SuBsTrInG", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" ends with: " SuBsTrInG" (case insensitive)
 String.tests.cpp:<line number>: passed: empty.empty() for: true
 String.tests.cpp:<line number>: passed: empty.size() == 0 for: 0 == 0
 String.tests.cpp:<line number>: passed: std::strcmp( empty.data(), "" ) == 0 for: 0 == 0
diff --git a/tests/SelfTest/Baselines/console.sw.approved.txt b/tests/SelfTest/Baselines/console.sw.approved.txt
index 6ec67e3f..f5324947 100644
--- a/tests/SelfTest/Baselines/console.sw.approved.txt
+++ b/tests/SelfTest/Baselines/console.sw.approved.txt
@@ -4521,7 +4521,7 @@ Matchers.tests.cpp:<line number>: PASSED:
   CHECK_THAT( testStringForMatching(), Equals( "this string contains 'ABC' as a substring", Catch::CaseSensitive::No ) )
 with expansion:
   "this string contains 'abc' as a substring" equals: "this string contains
-  'abc' as a substring" (case insensitive)
+  'ABC' as a substring" (case insensitive)
 
 -------------------------------------------------------------------------------
 Equals string matcher
@@ -4679,7 +4679,7 @@ Exception.tests.cpp:<line number>
 Exception.tests.cpp:<line number>: PASSED:
   REQUIRE_THROWS_WITH( thisThrows(), Equals( "expecteD Exception", Catch::CaseSensitive::No ) )
 with expansion:
-  "expected exception" equals: "expected exception" (case insensitive)
+  "expected exception" equals: "expecteD Exception" (case insensitive)
 
 -------------------------------------------------------------------------------
 Exception messages can be tested for
@@ -4706,7 +4706,7 @@ with expansion:
 Exception.tests.cpp:<line number>: PASSED:
   REQUIRE_THROWS_WITH( thisThrows(), ContainsSubstring( "exCept", Catch::CaseSensitive::No ) )
 with expansion:
-  "expected exception" contains: "except" (case insensitive)
+  "expected exception" contains: "exCept" (case insensitive)
 
 -------------------------------------------------------------------------------
 Exception thrown inside stringify does not fail the test
@@ -12195,7 +12195,7 @@ with expansion:
 Matchers.tests.cpp:<line number>: PASSED:
   CHECK_THAT( testStringForMatching(), ContainsSubstring( "aBC", Catch::CaseSensitive::No ) )
 with expansion:
-  "this string contains 'abc' as a substring" contains: "abc" (case
+  "this string contains 'abc' as a substring" contains: "aBC" (case
   insensitive)
 
 Matchers.tests.cpp:<line number>: PASSED:
@@ -12206,7 +12206,7 @@ with expansion:
 Matchers.tests.cpp:<line number>: PASSED:
   CHECK_THAT( testStringForMatching(), StartsWith( "THIS", Catch::CaseSensitive::No ) )
 with expansion:
-  "this string contains 'abc' as a substring" starts with: "this" (case
+  "this string contains 'abc' as a substring" starts with: "THIS" (case
   insensitive)
 
 Matchers.tests.cpp:<line number>: PASSED:
@@ -12217,7 +12217,7 @@ with expansion:
 Matchers.tests.cpp:<line number>: PASSED:
   CHECK_THAT( testStringForMatching(), EndsWith( " SuBsTrInG", Catch::CaseSensitive::No ) )
 with expansion:
-  "this string contains 'abc' as a substring" ends with: " substring" (case
+  "this string contains 'abc' as a substring" ends with: " SuBsTrInG" (case
   insensitive)
 
 -------------------------------------------------------------------------------
diff --git a/tests/SelfTest/Baselines/console.sw.multi.approved.txt b/tests/SelfTest/Baselines/console.sw.multi.approved.txt
index 9af23aa5..9dba6123 100644
--- a/tests/SelfTest/Baselines/console.sw.multi.approved.txt
+++ b/tests/SelfTest/Baselines/console.sw.multi.approved.txt
@@ -4519,7 +4519,7 @@ Matchers.tests.cpp:<line number>: PASSED:
   CHECK_THAT( testStringForMatching(), Equals( "this string contains 'ABC' as a substring", Catch::CaseSensitive::No ) )
 with expansion:
   "this string contains 'abc' as a substring" equals: "this string contains
-  'abc' as a substring" (case insensitive)
+  'ABC' as a substring" (case insensitive)
 
 -------------------------------------------------------------------------------
 Equals string matcher
@@ -4677,7 +4677,7 @@ Exception.tests.cpp:<line number>
 Exception.tests.cpp:<line number>: PASSED:
   REQUIRE_THROWS_WITH( thisThrows(), Equals( "expecteD Exception", Catch::CaseSensitive::No ) )
 with expansion:
-  "expected exception" equals: "expected exception" (case insensitive)
+  "expected exception" equals: "expecteD Exception" (case insensitive)
 
 -------------------------------------------------------------------------------
 Exception messages can be tested for
@@ -4704,7 +4704,7 @@ with expansion:
 Exception.tests.cpp:<line number>: PASSED:
   REQUIRE_THROWS_WITH( thisThrows(), ContainsSubstring( "exCept", Catch::CaseSensitive::No ) )
 with expansion:
-  "expected exception" contains: "except" (case insensitive)
+  "expected exception" contains: "exCept" (case insensitive)
 
 -------------------------------------------------------------------------------
 Exception thrown inside stringify does not fail the test
@@ -12188,7 +12188,7 @@ with expansion:
 Matchers.tests.cpp:<line number>: PASSED:
   CHECK_THAT( testStringForMatching(), ContainsSubstring( "aBC", Catch::CaseSensitive::No ) )
 with expansion:
-  "this string contains 'abc' as a substring" contains: "abc" (case
+  "this string contains 'abc' as a substring" contains: "aBC" (case
   insensitive)
 
 Matchers.tests.cpp:<line number>: PASSED:
@@ -12199,7 +12199,7 @@ with expansion:
 Matchers.tests.cpp:<line number>: PASSED:
   CHECK_THAT( testStringForMatching(), StartsWith( "THIS", Catch::CaseSensitive::No ) )
 with expansion:
-  "this string contains 'abc' as a substring" starts with: "this" (case
+  "this string contains 'abc' as a substring" starts with: "THIS" (case
   insensitive)
 
 Matchers.tests.cpp:<line number>: PASSED:
@@ -12210,7 +12210,7 @@ with expansion:
 Matchers.tests.cpp:<line number>: PASSED:
   CHECK_THAT( testStringForMatching(), EndsWith( " SuBsTrInG", Catch::CaseSensitive::No ) )
 with expansion:
-  "this string contains 'abc' as a substring" ends with: " substring" (case
+  "this string contains 'abc' as a substring" ends with: " SuBsTrInG" (case
   insensitive)
 
 -------------------------------------------------------------------------------
diff --git a/tests/SelfTest/Baselines/tap.sw.approved.txt b/tests/SelfTest/Baselines/tap.sw.approved.txt
index 69476eef..6fa5949e 100644
--- a/tests/SelfTest/Baselines/tap.sw.approved.txt
+++ b/tests/SelfTest/Baselines/tap.sw.approved.txt
@@ -1131,7 +1131,7 @@ ok {test-number} - x == Approx( 1.3 ) for: 1.30000000000000027 == Approx( 1.3000
 # Equals
 ok {test-number} - testStringForMatching(), Equals( "this string contains 'abc' as a substring" ) for: "this string contains 'abc' as a substring" equals: "this string contains 'abc' as a substring"
 # Equals
-ok {test-number} - testStringForMatching(), Equals( "this string contains 'ABC' as a substring", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" equals: "this string contains 'abc' as a substring" (case insensitive)
+ok {test-number} - testStringForMatching(), Equals( "this string contains 'ABC' as a substring", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" equals: "this string contains 'ABC' as a substring" (case insensitive)
 # Equals string matcher
 not ok {test-number} - testStringForMatching(), Equals( "this string contains 'ABC' as a substring" ) for: "this string contains 'abc' as a substring" equals: "this string contains 'ABC' as a substring"
 # Equals string matcher
@@ -1169,7 +1169,7 @@ ok {test-number} - throwsSpecialException( 2 ), SpecialException, MessageMatches
 # Exception messages can be tested for
 ok {test-number} - thisThrows(), "expected exception" for: "expected exception" equals: "expected exception"
 # Exception messages can be tested for
-ok {test-number} - thisThrows(), Equals( "expecteD Exception", Catch::CaseSensitive::No ) for: "expected exception" equals: "expected exception" (case insensitive)
+ok {test-number} - thisThrows(), Equals( "expecteD Exception", Catch::CaseSensitive::No ) for: "expected exception" equals: "expecteD Exception" (case insensitive)
 # Exception messages can be tested for
 ok {test-number} - thisThrows(), StartsWith( "expected" ) for: "expected exception" starts with: "expected"
 # Exception messages can be tested for
@@ -1177,7 +1177,7 @@ ok {test-number} - thisThrows(), EndsWith( "exception" ) for: "expected exceptio
 # Exception messages can be tested for
 ok {test-number} - thisThrows(), ContainsSubstring( "except" ) for: "expected exception" contains: "except"
 # Exception messages can be tested for
-ok {test-number} - thisThrows(), ContainsSubstring( "exCept", Catch::CaseSensitive::No ) for: "expected exception" contains: "except" (case insensitive)
+ok {test-number} - thisThrows(), ContainsSubstring( "exCept", Catch::CaseSensitive::No ) for: "expected exception" contains: "exCept" (case insensitive)
 # Exception thrown inside stringify does not fail the test
 ok {test-number} - tos == tos for: { stringification failed with an exception: "Invalid" } == { stringification failed with an exception: "Invalid" }
 # Exceptions matchers
@@ -2916,15 +2916,15 @@ ok {test-number} - testStringForMatching(), ContainsSubstring( "string", Catch::
 # String matchers
 ok {test-number} - testStringForMatching(), ContainsSubstring( "abc" ) for: "this string contains 'abc' as a substring" contains: "abc"
 # String matchers
-ok {test-number} - testStringForMatching(), ContainsSubstring( "aBC", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" contains: "abc" (case insensitive)
+ok {test-number} - testStringForMatching(), ContainsSubstring( "aBC", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" contains: "aBC" (case insensitive)
 # String matchers
 ok {test-number} - testStringForMatching(), StartsWith( "this" ) for: "this string contains 'abc' as a substring" starts with: "this"
 # String matchers
-ok {test-number} - testStringForMatching(), StartsWith( "THIS", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" starts with: "this" (case insensitive)
+ok {test-number} - testStringForMatching(), StartsWith( "THIS", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" starts with: "THIS" (case insensitive)
 # String matchers
 ok {test-number} - testStringForMatching(), EndsWith( "substring" ) for: "this string contains 'abc' as a substring" ends with: "substring"
 # String matchers
-ok {test-number} - testStringForMatching(), EndsWith( " SuBsTrInG", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" ends with: " substring" (case insensitive)
+ok {test-number} - testStringForMatching(), EndsWith( " SuBsTrInG", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" ends with: " SuBsTrInG" (case insensitive)
 # StringRef
 ok {test-number} - empty.empty() for: true
 # StringRef
diff --git a/tests/SelfTest/Baselines/tap.sw.multi.approved.txt b/tests/SelfTest/Baselines/tap.sw.multi.approved.txt
index 01b8a422..0a7d381a 100644
--- a/tests/SelfTest/Baselines/tap.sw.multi.approved.txt
+++ b/tests/SelfTest/Baselines/tap.sw.multi.approved.txt
@@ -1129,7 +1129,7 @@ ok {test-number} - x == Approx( 1.3 ) for: 1.30000000000000027 == Approx( 1.3000
 # Equals
 ok {test-number} - testStringForMatching(), Equals( "this string contains 'abc' as a substring" ) for: "this string contains 'abc' as a substring" equals: "this string contains 'abc' as a substring"
 # Equals
-ok {test-number} - testStringForMatching(), Equals( "this string contains 'ABC' as a substring", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" equals: "this string contains 'abc' as a substring" (case insensitive)
+ok {test-number} - testStringForMatching(), Equals( "this string contains 'ABC' as a substring", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" equals: "this string contains 'ABC' as a substring" (case insensitive)
 # Equals string matcher
 not ok {test-number} - testStringForMatching(), Equals( "this string contains 'ABC' as a substring" ) for: "this string contains 'abc' as a substring" equals: "this string contains 'ABC' as a substring"
 # Equals string matcher
@@ -1167,7 +1167,7 @@ ok {test-number} - throwsSpecialException( 2 ), SpecialException, MessageMatches
 # Exception messages can be tested for
 ok {test-number} - thisThrows(), "expected exception" for: "expected exception" equals: "expected exception"
 # Exception messages can be tested for
-ok {test-number} - thisThrows(), Equals( "expecteD Exception", Catch::CaseSensitive::No ) for: "expected exception" equals: "expected exception" (case insensitive)
+ok {test-number} - thisThrows(), Equals( "expecteD Exception", Catch::CaseSensitive::No ) for: "expected exception" equals: "expecteD Exception" (case insensitive)
 # Exception messages can be tested for
 ok {test-number} - thisThrows(), StartsWith( "expected" ) for: "expected exception" starts with: "expected"
 # Exception messages can be tested for
@@ -1175,7 +1175,7 @@ ok {test-number} - thisThrows(), EndsWith( "exception" ) for: "expected exceptio
 # Exception messages can be tested for
 ok {test-number} - thisThrows(), ContainsSubstring( "except" ) for: "expected exception" contains: "except"
 # Exception messages can be tested for
-ok {test-number} - thisThrows(), ContainsSubstring( "exCept", Catch::CaseSensitive::No ) for: "expected exception" contains: "except" (case insensitive)
+ok {test-number} - thisThrows(), ContainsSubstring( "exCept", Catch::CaseSensitive::No ) for: "expected exception" contains: "exCept" (case insensitive)
 # Exception thrown inside stringify does not fail the test
 ok {test-number} - tos == tos for: { stringification failed with an exception: "Invalid" } == { stringification failed with an exception: "Invalid" }
 # Exceptions matchers
@@ -2909,15 +2909,15 @@ ok {test-number} - testStringForMatching(), ContainsSubstring( "string", Catch::
 # String matchers
 ok {test-number} - testStringForMatching(), ContainsSubstring( "abc" ) for: "this string contains 'abc' as a substring" contains: "abc"
 # String matchers
-ok {test-number} - testStringForMatching(), ContainsSubstring( "aBC", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" contains: "abc" (case insensitive)
+ok {test-number} - testStringForMatching(), ContainsSubstring( "aBC", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" contains: "aBC" (case insensitive)
 # String matchers
 ok {test-number} - testStringForMatching(), StartsWith( "this" ) for: "this string contains 'abc' as a substring" starts with: "this"
 # String matchers
-ok {test-number} - testStringForMatching(), StartsWith( "THIS", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" starts with: "this" (case insensitive)
+ok {test-number} - testStringForMatching(), StartsWith( "THIS", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" starts with: "THIS" (case insensitive)
 # String matchers
 ok {test-number} - testStringForMatching(), EndsWith( "substring" ) for: "this string contains 'abc' as a substring" ends with: "substring"
 # String matchers
-ok {test-number} - testStringForMatching(), EndsWith( " SuBsTrInG", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" ends with: " substring" (case insensitive)
+ok {test-number} - testStringForMatching(), EndsWith( " SuBsTrInG", Catch::CaseSensitive::No ) for: "this string contains 'abc' as a substring" ends with: " SuBsTrInG" (case insensitive)
 # StringRef
 ok {test-number} - empty.empty() for: true
 # StringRef
diff --git a/tests/SelfTest/Baselines/xml.sw.approved.txt b/tests/SelfTest/Baselines/xml.sw.approved.txt
index d48496b9..81df5a53 100644
--- a/tests/SelfTest/Baselines/xml.sw.approved.txt
+++ b/tests/SelfTest/Baselines/xml.sw.approved.txt
@@ -5102,7 +5102,7 @@ Approx( 1.30000000000000004 )
         testStringForMatching(), Equals( "this string contains 'ABC' as a substring", Catch::CaseSensitive::No )
       </Original>
       <Expanded>
-        "this string contains 'abc' as a substring" equals: "this string contains 'abc' as a substring" (case insensitive)
+        "this string contains 'abc' as a substring" equals: "this string contains 'ABC' as a substring" (case insensitive)
       </Expanded>
     </Expression>
     <OverallResult success="true" skips="0"/>
@@ -5295,7 +5295,7 @@ Approx( 1.30000000000000004 )
           thisThrows(), Equals( "expecteD Exception", Catch::CaseSensitive::No )
         </Original>
         <Expanded>
-          "expected exception" equals: "expected exception" (case insensitive)
+          "expected exception" equals: "expecteD Exception" (case insensitive)
         </Expanded>
       </Expression>
       <OverallResults successes="1" failures="0" expectedFailures="0" skipped="false"/>
@@ -5330,7 +5330,7 @@ Approx( 1.30000000000000004 )
           thisThrows(), ContainsSubstring( "exCept", Catch::CaseSensitive::No )
         </Original>
         <Expanded>
-          "expected exception" contains: "except" (case insensitive)
+          "expected exception" contains: "exCept" (case insensitive)
         </Expanded>
       </Expression>
       <OverallResults successes="4" failures="0" expectedFailures="0" skipped="false"/>
@@ -14357,7 +14357,7 @@ Message from section two
         testStringForMatching(), ContainsSubstring( "aBC", Catch::CaseSensitive::No )
       </Original>
       <Expanded>
-        "this string contains 'abc' as a substring" contains: "abc" (case insensitive)
+        "this string contains 'abc' as a substring" contains: "aBC" (case insensitive)
       </Expanded>
     </Expression>
     <Expression success="true" type="CHECK_THAT" filename="tests/<exe-name>/UsageTests/Matchers.tests.cpp" >
@@ -14373,7 +14373,7 @@ Message from section two
         testStringForMatching(), StartsWith( "THIS", Catch::CaseSensitive::No )
       </Original>
       <Expanded>
-        "this string contains 'abc' as a substring" starts with: "this" (case insensitive)
+        "this string contains 'abc' as a substring" starts with: "THIS" (case insensitive)
       </Expanded>
     </Expression>
     <Expression success="true" type="CHECK_THAT" filename="tests/<exe-name>/UsageTests/Matchers.tests.cpp" >
@@ -14389,7 +14389,7 @@ Message from section two
         testStringForMatching(), EndsWith( " SuBsTrInG", Catch::CaseSensitive::No )
       </Original>
       <Expanded>
-        "this string contains 'abc' as a substring" ends with: " substring" (case insensitive)
+        "this string contains 'abc' as a substring" ends with: " SuBsTrInG" (case insensitive)
       </Expanded>
     </Expression>
     <OverallResult success="true" skips="0"/>
diff --git a/tests/SelfTest/Baselines/xml.sw.multi.approved.txt b/tests/SelfTest/Baselines/xml.sw.multi.approved.txt
index db82d34d..5888529c 100644
--- a/tests/SelfTest/Baselines/xml.sw.multi.approved.txt
+++ b/tests/SelfTest/Baselines/xml.sw.multi.approved.txt
@@ -5102,7 +5102,7 @@ Approx( 1.30000000000000004 )
         testStringForMatching(), Equals( "this string contains 'ABC' as a substring", Catch::CaseSensitive::No )
       </Original>
       <Expanded>
-        "this string contains 'abc' as a substring" equals: "this string contains 'abc' as a substring" (case insensitive)
+        "this string contains 'abc' as a substring" equals: "this string contains 'ABC' as a substring" (case insensitive)
       </Expanded>
     </Expression>
     <OverallResult success="true" skips="0"/>
@@ -5295,7 +5295,7 @@ Approx( 1.30000000000000004 )
           thisThrows(), Equals( "expecteD Exception", Catch::CaseSensitive::No )
         </Original>
         <Expanded>
-          "expected exception" equals: "expected exception" (case insensitive)
+          "expected exception" equals: "expecteD Exception" (case insensitive)
         </Expanded>
       </Expression>
       <OverallResults successes="1" failures="0" expectedFailures="0" skipped="false"/>
@@ -5330,7 +5330,7 @@ Approx( 1.30000000000000004 )
           thisThrows(), ContainsSubstring( "exCept", Catch::CaseSensitive::No )
         </Original>
         <Expanded>
-          "expected exception" contains: "except" (case insensitive)
+          "expected exception" contains: "exCept" (case insensitive)
         </Expanded>
       </Expression>
       <OverallResults successes="4" failures="0" expectedFailures="0" skipped="false"/>
@@ -14357,7 +14357,7 @@ Message from section two
         testStringForMatching(), ContainsSubstring( "aBC", Catch::CaseSensitive::No )
       </Original>
       <Expanded>
-        "this string contains 'abc' as a substring" contains: "abc" (case insensitive)
+        "this string contains 'abc' as a substring" contains: "aBC" (case insensitive)
       </Expanded>
     </Expression>
     <Expression success="true" type="CHECK_THAT" filename="tests/<exe-name>/UsageTests/Matchers.tests.cpp" >
@@ -14373,7 +14373,7 @@ Message from section two
         testStringForMatching(), StartsWith( "THIS", Catch::CaseSensitive::No )
       </Original>
       <Expanded>
-        "this string contains 'abc' as a substring" starts with: "this" (case insensitive)
+        "this string contains 'abc' as a substring" starts with: "THIS" (case insensitive)
       </Expanded>
     </Expression>
     <Expression success="true" type="CHECK_THAT" filename="tests/<exe-name>/UsageTests/Matchers.tests.cpp" >
@@ -14389,7 +14389,7 @@ Message from section two
         testStringForMatching(), EndsWith( " SuBsTrInG", Catch::CaseSensitive::No )
       </Original>
       <Expanded>
-        "this string contains 'abc' as a substring" ends with: " substring" (case insensitive)
+        "this string contains 'abc' as a substring" ends with: " SuBsTrInG" (case insensitive)
       </Expanded>
     </Expression>
     <OverallResult success="true" skips="0"/>