Allow generators to declare themselves (infinite)

This will be useful later to implement warning on infinitely
running `GENERATE` expressions.

2 files changed, 11 insertions, 0 deletions

diff --git a/src/catch2/interfaces/catch_interfaces_generatortracker.cpp b/src/catch2/interfaces/catch_interfaces_generatortracker.cpp
index 4ac23ddb..8442be4e 100644
--- a/src/catch2/interfaces/catch_interfaces_generatortracker.cpp
+++ b/src/catch2/interfaces/catch_interfaces_generatortracker.cpp
@@ -55,5 +55,7 @@ namespace Catch {
             return m_stringReprCache;
         }
 
+        bool GeneratorUntypedBase::isFinite() const { return true; }
+
     } // namespace Generators
 } // namespace Catch
diff --git a/src/catch2/interfaces/catch_interfaces_generatortracker.hpp b/src/catch2/interfaces/catch_interfaces_generatortracker.hpp
index eb3871bc..12cb9d79 100644
--- a/src/catch2/interfaces/catch_interfaces_generatortracker.hpp
+++ b/src/catch2/interfaces/catch_interfaces_generatortracker.hpp
@@ -88,6 +88,15 @@ namespace Catch {
              * comes first.
              */
             StringRef currentElementAsString() const;
+
+            /**
+             * Returns true if calls to `next` will eventually return false
+             *
+             * Note that for backwards compatibility this is currently defaulted
+             * to return `true`, but in the future all generators will have to
+             * provide their own implementation.
+             */
+            virtual bool isFinite() const;
         };
         using GeneratorBasePtr = Catch::Detail::unique_ptr<GeneratorUntypedBase>;