Use C++11 compatible std::is_same operations

[gsjaardema]

The operator() member function of std::is_same was added in C++14. For C++11, the ::value needs to be used instead.

I agree that my contributions are licensed under the {fmt} license, and agree to future changes to the licensing.

[vitaut]

This is a ctor and not operator() call and conversion to bool is available in C++11.

[vitaut]

Does it fail with brace initialization std::is_same<T, float>{} too?

[gsjaardema]

Yes, but it isn't a compilation failure, but the static assert triggers:

/scratch/xxxxxxx/xxxxxx-test/fmt/format-inl.h(1082): error: static assertion failed with ""
      static_assert(!std::is_same<T, float>{}, "");
      ^
          detected during:
            instantiation of "void fmt::v6::internal::basic_writer<Range>::write(T, fmt::v6::internal::basic_writer<Range>::format_specs) [with Range=fmt::v6::buffer_range<char>, T=float, <unnamed>=0]" at line 1955 of "/scratch/yyyyyy/xxxxxx-test/fmt/format.h"
            instantiation of "fmt::v6::internal::arg_formatter_base<Range, ErrorHandler>::iterator fmt::v6::internal::arg_formatter_base<Range, ErrorHandler>::operator()(T) [with Range=fmt::v6::buffer_range<char>, ErrorHandler=fmt::v6::internal::error_handler, T=float, <unnamed>=0]" at line 1082 of "/scratch/yyyyyy/xxxxxx-test/fmt/core.h"
            instantiation of "auto fmt::v6::visit_format_arg(Visitor &&, const fmt::v6::basic_format_arg<Context> &)->decltype((<expression>)) [with Visitor=fmt::v6::arg_formatter<fmt::v6::buffer_range<char>>, Context=fmt::v6::format_context]" at line 3266 of "/scratch/yyyyyy/xxxxxx-test/fmt/format.h"
            instantiation of "void fmt::v6::format_handler<ArgFormatter, Char, Context>::on_replacement_field(const Char *) [with ArgFormatter=fmt::v6::arg_formatter<fmt::v6::buffer_range<char>>, Char=char, Context=fmt::v6::format_context]" at line 2673 of "/scratch/yyyyyy/xxxxxx-test/fmt/format.h"
            instantiation of "void fmt::v6::internal::parse_format_string<IS_CONSTEXPR,Char,Handler>(fmt::v6::basic_string_view<Char>, Handler &&) [with IS_CONSTEXPR=false, Char=char, Handler=fmt::v6::format_handler<fmt::v6::arg_formatter<fmt::v6::buffer_range<char>>, char, fmt::v6::format_context> &]" at line 3300 of "/scratch/yyyyyy/xxxxxx-test/fmt/format.h"
            instantiation of "Context::iterator fmt::v6::vformat_to<ArgFormatter,Char,Context>(ArgFormatter::range, fmt::v6::basic_string_view<Char>, fmt::v6::basic_format_args<Context>, fmt::v6::internal::locale_ref) [with ArgFormatter=fmt::v6::arg_formatter<fmt::v6::buffer_range<char>>, Char=char, Context=fmt::v6::format_context]" at line 3413 of "/scratch/yyyyyy/xxxxxx-test/fmt/format.h"
            instantiation of "fmt::v6::basic_format_context<std::back_insert_iterator<fmt::v6::internal::buffer<Char>>, Char>::iterator fmt::v6::internal::vformat_to(fmt::v6::internal::buffer<Char> &, fmt::v6::basic_string_view<Char>, fmt::v6::basic_format_args<fmt::v6::buffer_context<Char>>) [with Char=char]" at line 1424

compilation aborted for /scratch/yyyyyy/xxxxxx-test/Ioss_FaceGenerator.C (code 2)

[gsjaardema]

Thanks.