1//
2// Copyright (c) 2012 The ANGLE Project Authors. All rights reserved.
3// Use of this source code is governed by a BSD-style license that can be
4// found in the LICENSE file.
5//
6
7// numeric_lex.h: Functions to extract numeric values from string.
8
9#ifndef COMPILER_PREPROCESSOR_NUMERICLEX_H_
10#define COMPILER_PREPROCESSOR_NUMERICLEX_H_
11
12#include <sstream>
13
14namespace angle
15{
16
17namespace pp
18{
19
20inline std::ios::fmtflags numeric_base_int(const std::string &str)
21{
22 if ((str.size() >= 2) && (str[0] == '0') && (str[1] == 'x' || str[1] == 'X'))
23 {
24 return std::ios::hex;
25 }
26 if ((str.size() >= 1) && (str[0] == '0'))
27 {
28 return std::ios::oct;
29 }
30 return std::ios::dec;
31}
32
33// The following functions parse the given string to extract a numerical
34// value of the given type. These functions assume that the string is
35// of the correct form. They can only fail if the parsed value is too big,
36// in which case false is returned.
37
38template <typename IntType>
39bool numeric_lex_int(const std::string &str, IntType *value)
40{
41 std::istringstream stream(str);
42 // This should not be necessary, but MSVS has a buggy implementation.
43 // It returns incorrect results if the base is not specified.
44 stream.setf(numeric_base_int(str), std::ios::basefield);
45
46 stream >> (*value);
47 return !stream.fail();
48}
49
50} // namespace pp
51
52} // namespace angle
53
54#endif // COMPILER_PREPROCESSOR_NUMERICLEX_H_
55