ClickHouse/base/common/wide_integer_to_string.h

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#pragma once
#include <string>
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#include <ostream>
#include <fmt/format.h>
#include "wide_integer.h"
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namespace wide
{
template <size_t Bits, typename Signed>
inline std::string to_string(const integer<Bits, Signed> & n)
{
std::string res;
if (integer<Bits, Signed>::_impl::operator_eq(n, 0U))
return "0";
integer<Bits, unsigned> t;
bool is_neg = integer<Bits, Signed>::_impl::is_negative(n);
if (is_neg)
t = integer<Bits, Signed>::_impl::operator_unary_minus(n);
else
t = n;
while (!integer<Bits, unsigned>::_impl::operator_eq(t, 0U))
{
res.insert(res.begin(), '0' + char(integer<Bits, unsigned>::_impl::operator_percent(t, 10U)));
t = integer<Bits, unsigned>::_impl::operator_slash(t, 10U);
}
if (is_neg)
res.insert(res.begin(), '-');
return res;
}
}
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template <size_t Bits, typename Signed>
std::ostream & operator<<(std::ostream & out, const wide::integer<Bits, Signed> & value)
{
return out << to_string(value);
}
/// See https://fmt.dev/latest/api.html#formatting-user-defined-types
template <size_t Bits, typename Signed>
struct fmt::formatter<wide::integer<Bits, Signed>>
{
constexpr auto parse(format_parse_context & ctx)
{
auto it = ctx.begin();
auto end = ctx.end();
/// Only support {}.
if (it != end && *it != '}')
throw format_error("invalid format");
return it;
}
template <typename FormatContext>
auto format(const wide::integer<Bits, Signed> & value, FormatContext & ctx)
{
return format_to(ctx.out(), "{}", to_string(value));
}
};