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#ifndef COMPONENTS_MISC_STRINGS_FORMAT_H
#define COMPONENTS_MISC_STRINGS_FORMAT_H
#include <MyGUI_UString.h>
#include <cerrno>
#include <cstdio>
#include <cstring>
#include <stdexcept>
#include <string>
#include <string_view>
#include <system_error>
#include <vector>
namespace Misc::StringUtils
{
namespace Details
{
// Allow to convert complex arguments to C-style strings for format() function
template <typename T>
T argument(T value) noexcept
{
static_assert(!std::is_same_v<T, std::string_view>, "std::string_view is not supported");
static_assert(!std::is_same_v<T, MyGUI::UString>, "MyGUI::UString is not supported");
return value;
}
template <typename T>
T const* argument(std::basic_string<T> const& value) noexcept
{
return value.c_str();
}
template <class T>
T nullTerminated(T value) noexcept
{
return value;
}
template <class T>
std::basic_string<T> nullTerminated(const std::basic_string_view<T>& value) noexcept
{
// Ensure string_view arguments are null-terminated by creating a string
// TODO: Use a format function that doesn't require this workaround
return std::string{ value };
}
// Requires some C++11 features:
// 1. std::string needs to be contiguous
// 2. std::snprintf with zero size (second argument) returns an output string size
// 3. variadic templates support
template <typename... Args>
std::string format(const char* fmt, Args const&... args)
{
const int size = std::snprintf(nullptr, 0, fmt, argument(args)...);
if (size < 0)
throw std::system_error(errno, std::generic_category(), "Failed to compute resulting string size");
// Note: sprintf also writes a trailing null character. We should remove it.
std::string ret(static_cast<std::size_t>(size) + 1, '\0');
if (std::sprintf(ret.data(), fmt, argument(args)...) < 0)
throw std::system_error(errno, std::generic_category(), "Failed to format string");
ret.erase(static_cast<std::size_t>(size));
return ret;
}
}
template <typename... Args>
std::string format(const char* fmt, Args const&... args)
{
return Details::format(fmt, Details::nullTerminated(args)...);
}
template <typename... Args>
std::string format(const std::string& fmt, Args const&... args)
{
return Details::format(fmt.c_str(), Details::nullTerminated(args)...);
}
}
#endif
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