// Formatting library for C++ - custom argument formatter tests // // Copyright (c) 2012 - present, Victor Zverovich // All rights reserved. // // For the license information refer to format.h. #include "fmt/format.h" #include "gtest-extra.h" // MSVC 2013 is known to be broken. #if !FMT_MSC_VER || FMT_MSC_VER > 1800 // A custom argument formatter that doesn't print `-` for floating-point values // rounded to 0. class custom_arg_formatter : public fmt::arg_formatter<fmt::back_insert_range<fmt::internal::buffer>> { public: typedef fmt::back_insert_range<fmt::internal::buffer> range; typedef fmt::arg_formatter<range> base; custom_arg_formatter( fmt::format_context &ctx, fmt::format_specs *s = FMT_NULL) : base(ctx, s) {} using base::operator(); iterator operator()(double value) { // Comparing a float to 0.0 is safe if (round(value * pow(10, spec()->precision())) == 0.0) value = 0; return base::operator()(value); } }; std::string custom_vformat(fmt::string_view format_str, fmt::format_args args) { fmt::memory_buffer buffer; // Pass custom argument formatter as a template arg to vwrite. fmt::vformat_to<custom_arg_formatter>(buffer, format_str, args); return std::string(buffer.data(), buffer.size()); } template <typename... Args> std::string custom_format(const char *format_str, const Args & ... args) { auto va = fmt::make_format_args(args...); return custom_vformat(format_str, va); } TEST(CustomFormatterTest, Format) { EXPECT_EQ("0.00", custom_format("{:.2f}", -.00001)); } #endif