libstdc++: exception.h Source File

libstdc++

exception.h
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1// Exception Handling support header for -*- C++ -*-
2
3// Copyright (C) 2016-2026 Free Software Foundation, Inc.
4//
5// This file is part of GCC.
6//
7// GCC is free software; you can redistribute it and/or modify
8// it under the terms of the GNU General Public License as published by
9// the Free Software Foundation; either version 3, or (at your option)
10// any later version.
11//
12// GCC is distributed in the hope that it will be useful,
13// but WITHOUT ANY WARRANTY; without even the implied warranty of
14// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15// GNU General Public License for more details.
16//
17// Under Section 7 of GPL version 3, you are granted additional
18// permissions described in the GCC Runtime Library Exception, version
19// 3.1, as published by the Free Software Foundation.
20
21// You should have received a copy of the GNU General Public License and
22// a copy of the GCC Runtime Library Exception along with this program;
23// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
24// <http://www.gnu.org/licenses/>.
25
26/** @file bits/exception.h
27 * This is an internal header file, included by other library headers.
28 * Do not attempt to use it directly.
29 */
30
31#ifndef __EXCEPTION_H
32#define __EXCEPTION_H 1
33
34#ifdef _GLIBCXX_SYSHDR
35#pragma GCC system_header
36#endif
37
38#include <bits/c++config.h>
39
40extern "C++" {
41
42namespace std _GLIBCXX_VISIBILITY(default)
43{
44 /**
45 * @defgroup exceptions Exceptions
46 * @ingroup diagnostics
47 * @since C++98
48 *
49 * Classes and functions for reporting errors via exceptions.
50 * @{
51 */
52
53 /**
54 * @brief Base class for all library exceptions.
55 *
56 * This is the base class for all exceptions thrown by the standard
57 * library, and by certain language expressions. You are free to derive
58 * your own %exception classes, or use a different hierarchy, or to
59 * throw non-class data (e.g., fundamental types).
60 */
61 class exception
62 {
63 public:
64 _GLIBCXX26_CONSTEXPR exception() _GLIBCXX_NOTHROW { }
65#if __cplusplus >= 202400L
66 [[__gnu__::__gnu_inline__]]
67 constexpr inline virtual ~exception() _GLIBCXX_TXN_SAFE_DYN noexcept {}
68#else
69 virtual ~exception() _GLIBCXX_TXN_SAFE_DYN _GLIBCXX_NOTHROW;
70#endif
71#if __cplusplus >= 201103L
72 _GLIBCXX26_CONSTEXPR exception(const exception&) = default;
73 _GLIBCXX26_CONSTEXPR exception& operator=(const exception&) = default;
74 _GLIBCXX26_CONSTEXPR exception(exception&&) = default;
75 _GLIBCXX26_CONSTEXPR exception& operator=(exception&&) = default;
76#endif
77
78 /** Returns a C-style character string describing the general cause
79 * of the current error. */
80#if __cplusplus >= 202400L
81 [[__gnu__::__gnu_inline__]]
82 constexpr inline virtual const char*
83 what() const _GLIBCXX_TXN_SAFE_DYN noexcept { return "std::exception"; }
84#else
85 virtual const char*
86 what() const _GLIBCXX_TXN_SAFE_DYN _GLIBCXX_NOTHROW;
87#endif
88 };
89
90 /// @}
91
92} // namespace std
93
94}
95
96#endif
c++config.h
std
ISO C++ entities toplevel namespace is std.
std::exception::what
virtual constexpr const char * what() const noexcept
Definition exception.h:83