1// This header intentionally has no include guards.
2//
3// Copyright (c) 2001-2009, 2012 Peter Dimov
4//
5// Distributed under the Boost Software License, Version 1.0.
6// See accompanying file LICENSE_1_0.txt or copy at
7// http://www.boost.org/LICENSE_1_0.txt
8
9#if !defined( BOOST_NO_CXX11_EXPLICIT_CONVERSION_OPERATORS ) && !defined( BOOST_NO_CXX11_NULLPTR )\
10 && !(defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, <= 0x5130))
11
12 explicit operator bool () const BOOST_NOEXCEPT
13 {
14 return px != 0;
15 }
16
17#elif ( defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, < 0x570) ) || defined(__CINT__)
18
19 operator bool () const BOOST_NOEXCEPT
20 {
21 return px != 0;
22 }
23
24#elif defined( _MANAGED )
25
26 static void unspecified_bool( this_type*** )
27 {
28 }
29
30 typedef void (*unspecified_bool_type)( this_type*** );
31
32 operator unspecified_bool_type() const BOOST_NOEXCEPT
33 {
34 return px == 0? 0: unspecified_bool;
35 }
36
37#elif \
38 ( defined(__MWERKS__) && BOOST_WORKAROUND(__MWERKS__, < 0x3200) ) || \
39 ( defined(__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ < 304) ) || \
40 ( defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, <= 0x590) )
41
42 typedef element_type * (this_type::*unspecified_bool_type)() const;
43
44 operator unspecified_bool_type() const BOOST_NOEXCEPT
45 {
46 return px == 0? 0: &this_type::get;
47 }
48
49#else
50
51 typedef element_type * this_type::*unspecified_bool_type;
52
53 operator unspecified_bool_type() const BOOST_NOEXCEPT
54 {
55 return px == 0? 0: &this_type::px;
56 }
57
58#endif
59
60 // operator! is redundant, but some compilers need it
61 bool operator! () const BOOST_NOEXCEPT
62 {
63 return px == 0;
64 }
65

source code of boost/boost/smart_ptr/detail/operator_bool.hpp