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//
// Copyright 2012 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// numeric_lex.h: Functions to extract numeric values from string.
#ifndef COMPILER_PREPROCESSOR_NUMERICLEX_H_
#define COMPILER_PREPROCESSOR_NUMERICLEX_H_
#include <sstream>
namespace angle
{
namespace pp
{
inline std::ios::fmtflags numeric_base_int(const std::string &str)
{
if ((str.size() >= 2) && (str[0] == '0') && (str[1] == 'x' || str[1] == 'X'))
{
return std::ios::hex;
}
if ((str.size() >= 1) && (str[0] == '0'))
{
return std::ios::oct;
}
return std::ios::dec;
}
// The following functions parse the given string to extract a numerical
// value of the given type. These functions assume that the string is
// of the correct form. They can only fail if the parsed value is too big,
// in which case false is returned.
template <typename IntType>
bool numeric_lex_int(const std::string &str, IntType *value)
{
std::istringstream stream(str);
// This should not be necessary, but MSVS has a buggy implementation.
// It returns incorrect results if the base is not specified.
stream.setf(numeric_base_int(str), std::ios::basefield);
stream >> (*value);
return !stream.fail();
}
} // namespace pp
} // namespace angle
#endif // COMPILER_PREPROCESSOR_NUMERICLEX_H_