ClickHouse/src/IO/DoubleConverter.h
2022-10-07 21:49:08 +02:00

47 lines
1.3 KiB
C++

#pragma once
#ifdef __clang__
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdouble-promotion"
#endif
#include <base/defines.h>
#include <double-conversion/double-conversion.h>
#include <boost/noncopyable.hpp>
#ifdef __clang__
#pragma clang diagnostic pop
#endif
namespace DB
{
template <bool emit_decimal_point> struct DoubleToStringConverterFlags
{
static constexpr auto flags = double_conversion::DoubleToStringConverter::NO_FLAGS;
};
template <> struct DoubleToStringConverterFlags<true>
{
static constexpr auto flags = double_conversion::DoubleToStringConverter::EMIT_TRAILING_DECIMAL_POINT;
};
template <bool emit_decimal_point>
class DoubleConverter : private boost::noncopyable
{
DoubleConverter() = default;
public:
/// Sign (1 byte) + DigitsBeforePoint + point (1 byte) + DigitsAfterPoint + zero byte.
/// See comment to DoubleToStringConverter::ToFixed method for explanation.
static constexpr auto MAX_REPRESENTATION_LENGTH =
1 + double_conversion::DoubleToStringConverter::kMaxFixedDigitsBeforePoint +
1 + double_conversion::DoubleToStringConverter::kMaxFixedDigitsAfterPoint + 1;
using BufferType = char[MAX_REPRESENTATION_LENGTH];
static const double_conversion::DoubleToStringConverter & instance();
};
}