fmt/test/custom-formatter-test.cc
2018-01-21 14:30:38 -08:00

53 lines
1.5 KiB
C++

/*
Custom argument formatter tests
Copyright (c) 2016, Victor Zverovich
All rights reserved.
For the license information refer to format.h.
*/
#include "fmt/printf.h"
#include "gtest-extra.h"
using fmt::printf_arg_formatter;
// A custom argument formatter that doesn't print `-` for floating-point values
// rounded to 0.
class CustomArgFormatter :
public fmt::arg_formatter<fmt::back_insert_range<fmt::internal::buffer>> {
public:
using range = fmt::back_insert_range<fmt::internal::buffer>;
using iterator = decltype(std::declval<range>().begin());
using base = fmt::arg_formatter<range>;
CustomArgFormatter(fmt::basic_context<iterator, char> &ctx,
fmt::format_specs &s)
: base(ctx, s) {}
using base::operator();
void operator()(double value) {
if (round(value * pow(10, spec().precision())) == 0)
value = 0;
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::do_vformat_to<CustomArgFormatter>(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_args(args...);
return custom_vformat(format_str, va);
}
TEST(CustomFormatterTest, Format) {
EXPECT_EQ("0.00", custom_format("{:.2f}", -.00001));
}