Expand FMT_FORMAT_AS to include implicit conversions (#4055)

Allows (for example) types convertible to std::string_view to inherit
from the fmt::formatter<fmt::string_view> to work etc.
This commit is contained in:
Justin Riddell
2024-07-14 17:51:49 +01:00
committed by GitHub
parent c9102619da
commit 5ef93a9f80
2 changed files with 23 additions and 3 deletions
+14
View File
@@ -1650,6 +1650,20 @@ TEST(format_test, format_explicitly_convertible_to_std_string_view) {
EXPECT_EQ("'foo'",
fmt::format("{}", explicitly_convertible_to_std_string_view()));
}
struct convertible_to_std_string_view {
operator std::string_view() const noexcept { return "Hi there"; }
};
FMT_BEGIN_NAMESPACE
template <>
class formatter<convertible_to_std_string_view>
: public formatter<std::string_view> {};
FMT_END_NAMESPACE
TEST(format_test, format_implicitly_convertible_and_inherits_string_view) {
static_assert(fmt::is_formattable<convertible_to_std_string_view>{}, "");
EXPECT_EQ("Hi there", fmt::format("{}", convertible_to_std_string_view{}));
}
#endif
class Answer {};