1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/angle/src/compiler/preprocessor/numeric_lex.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,61 @@
1.4 +//
1.5 +// Copyright (c) 2012 The ANGLE Project Authors. All rights reserved.
1.6 +// Use of this source code is governed by a BSD-style license that can be
1.7 +// found in the LICENSE file.
1.8 +//
1.9 +
1.10 +// numeric_lex.h: Functions to extract numeric values from string.
1.11 +
1.12 +#ifndef COMPILER_PREPROCESSOR_NUMERIC_LEX_H_
1.13 +#define COMPILER_PREPROCESSOR_NUMERIC_LEX_H_
1.14 +
1.15 +#include <sstream>
1.16 +
1.17 +namespace pp {
1.18 +
1.19 +inline std::ios::fmtflags numeric_base_int(const std::string& str)
1.20 +{
1.21 + if ((str.size() >= 2) &&
1.22 + (str[0] == '0') &&
1.23 + (str[1] == 'x' || str[1] == 'X'))
1.24 + {
1.25 + return std::ios::hex;
1.26 + }
1.27 + else if ((str.size() >= 1) && (str[0] == '0'))
1.28 + {
1.29 + return std::ios::oct;
1.30 + }
1.31 + return std::ios::dec;
1.32 +}
1.33 +
1.34 +// The following functions parse the given string to extract a numerical
1.35 +// value of the given type. These functions assume that the string is
1.36 +// of the correct form. They can only fail if the parsed value is too big,
1.37 +// in which case false is returned.
1.38 +
1.39 +template<typename IntType>
1.40 +bool numeric_lex_int(const std::string& str, IntType* value)
1.41 +{
1.42 + std::istringstream stream(str);
1.43 + // This should not be necessary, but MSVS has a buggy implementation.
1.44 + // It returns incorrect results if the base is not specified.
1.45 + stream.setf(numeric_base_int(str), std::ios::basefield);
1.46 +
1.47 + stream >> (*value);
1.48 + return !stream.fail();
1.49 +}
1.50 +
1.51 +template<typename FloatType>
1.52 +bool numeric_lex_float(const std::string& str, FloatType* value)
1.53 +{
1.54 + std::istringstream stream(str);
1.55 + // Force "C" locale so that decimal character is always '.', and
1.56 + // not dependent on the current locale.
1.57 + stream.imbue(std::locale::classic());
1.58 +
1.59 + stream >> (*value);
1.60 + return !stream.fail();
1.61 +}
1.62 +
1.63 +} // namespace pp.
1.64 +#endif // COMPILER_PREPROCESSOR_NUMERIC_LEX_H_
