Add StringMaker for std::variant, std::monostate (#1380)

The StringMaker is off by default and can be enabled by a new macro `CATCH_CONFIG_ENABLE_VARIANT_STRINGMAKER`, to avoid increasing the footprint of stringification machinery by default.
This commit is contained in:
melak47
2018-09-20 13:13:35 +01:00
committed by Martin Hořeňovský
parent a575536abe
commit c638c57209
6 changed files with 139 additions and 2 deletions

View File

@@ -163,6 +163,23 @@
#endif
#endif
////////////////////////////////////////////////////////////////////////////////
// Check if variant is available and usable
#if defined(__has_include)
# if __has_include(<variant>) && defined(CATCH_CPP17_OR_GREATER)
# if defined(__clang__) && (__clang_major__ < 8)
// work around clang bug with libstdc++ https://bugs.llvm.org/show_bug.cgi?id=31852
// fix should be in clang 8, workaround in libstdc++ 8.2
# include <ciso646>
# if defined(__GLIBCXX__) && defined(_GLIBCXX_RELEASE) && (_GLIBCXX_RELEASE < 9)
# define CATCH_CONFIG_NO_CPP17_VARIANT
# else
# define CATCH_INTERNAL_CONFIG_CPP17_VARIANT
# endif // defined(__GLIBCXX__) && defined(_GLIBCXX_RELEASE) && (_GLIBCXX_RELEASE < 9)
# endif // defined(__clang__) && (__clang_major__ < 8)
# endif // __has_include(<variant>) && defined(CATCH_CPP17_OR_GREATER)
#endif // __has_include
#if defined(CATCH_INTERNAL_CONFIG_COUNTER) && !defined(CATCH_CONFIG_NO_COUNTER) && !defined(CATCH_CONFIG_COUNTER)
# define CATCH_CONFIG_COUNTER
@@ -191,6 +208,10 @@
# define CATCH_CONFIG_CPP17_STRING_VIEW
#endif
#if defined(CATCH_INTERNAL_CONFIG_CPP17_VARIANT) && !defined(CATCH_CONFIG_NO_CPP17_VARIANT) && !defined(CATCH_CONFIG_CPP17_VARIANT)
# define CATCH_CONFIG_CPP17_VARIANT
#endif
#if defined(CATCH_CONFIG_EXPERIMENTAL_REDIRECT)
# define CATCH_INTERNAL_CONFIG_NEW_CAPTURE
#endif

View File

@@ -354,6 +354,7 @@ namespace Catch {
#if defined(CATCH_CONFIG_ENABLE_ALL_STRINGMAKERS)
# define CATCH_CONFIG_ENABLE_PAIR_STRINGMAKER
# define CATCH_CONFIG_ENABLE_TUPLE_STRINGMAKER
# define CATCH_CONFIG_ENABLE_VARIANT_STRINGMAKER
# define CATCH_CONFIG_ENABLE_CHRONO_STRINGMAKER
#endif
@@ -418,6 +419,34 @@ namespace Catch {
}
#endif // CATCH_CONFIG_ENABLE_TUPLE_STRINGMAKER
#if defined(CATCH_CONFIG_ENABLE_VARIANT_STRINGMAKER) && defined(CATCH_CONFIG_CPP17_VARIANT)
#include <variant>
namespace Catch {
template<>
struct StringMaker<std::monostate> {
static std::string convert(const std::monostate&) {
return "{ }";
}
};
template<typename... Elements>
struct StringMaker<std::variant<Elements...>> {
static std::string convert(const std::variant<Elements...>& variant) {
if (variant.valueless_by_exception()) {
return "{valueless variant}";
} else {
return std::visit(
[](const auto& value) {
return ::Catch::Detail::stringify(value);
},
variant
);
}
}
};
}
#endif // CATCH_CONFIG_ENABLE_VARIANT_STRINGMAKER
namespace Catch {
struct not_this_one {}; // Tag type for detecting which begin/ end are being selected