Say C++17 everywhere the project describes itselfchore/cpp17-descriptions

The move to C++17 left a trail of older claims. The Runner's own
.clang-format still said c++20; the result is byte for byte the same under
either value. Premake and Xmake still compiled the library as C++20 and
the main library as C++14, which meant their CI jobs were not testing the
language the project promises. Both now use C++17 for every target.

The rest is text: the Meson pkg-config description claimed C++14, comments
in the CMake and Meson files explained requirements that no longer exist,
.clang-tidy gave C++14 as the reason for two exclusions, issue templates
asked for C++20 samples, and the example headers named -std=c++14 and
catch2-with-main. The release notes and the migration guide state the
C++17 minimum. Doxygen's brief called the project "Catch2's test API",
which presents it as Catch2. Meson declared only BSL-1.0; it now names both
licenses of the tree. The amalgamated files are regenerated.

1 files changed, 1 insertions, 1 deletions

diff --git a/docs/migrate-v2-to-v3.md b/docs/migrate-v2-to-v3.md
index bd030523..9ec1f1c7 100644
--- a/docs/migrate-v2-to-v3.md
+++ b/docs/migrate-v2-to-v3.md
@@ -7,7 +7,7 @@
 v3 is the next major version of Catch2 and brings three significant changes:
  * Catch2 is now split into multiple headers
  * Catch2 is now compiled as a static library
- * C++14 is the minimum required C++ version
+ * C++17 is the minimum required C++ version
 
 There are many reasons why we decided to go from the old single-header
 distribution model to a more standard library distribution model. The