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assert.hpp |
BOOST_ASSERT
BOOST_ASSERT_MSG
BOOST_VERIFY
The header <boost/assert.hpp> defines the macro BOOST_ASSERT, which is similar to the standard assert macro defined in <cassert>. The macro is intended to be used in both Boost libraries and user code.
By default, BOOST_ASSERT(expr) is equivalent to assert(expr).
If the macro BOOST_DISABLE_ASSERTS is defined when <boost/assert.hpp> is included, BOOST_ASSERT(expr) is defined as ((void)0). This allows users to selectively disable BOOST_ASSERT without affecting the definition of the standard assert.
If the macro BOOST_ENABLE_ASSERT_HANDLER is defined when <boost/assert.hpp> is included, BOOST_ASSERT(expr) evaluates expr and, if the result is false, evaluates the expression
::boost::assertion_failed(#expr, BOOST_CURRENT_FUNCTION, __FILE__, __LINE__)
assertion_failed is declared in <boost/assert.hpp> as
namespace boost
{
void assertion_failed(char const * expr, char const * function, char const * file, long line);
}
but it is never defined. The user is expected to supply an appropriate definition.
As is the case with <cassert>, <boost/assert.hpp> can be included multiple times in a single translation unit. BOOST_ASSERT will be redefined each time as specified above.
The header <boost/assert.hpp> defines the macro BOOST_ASSERT_MSG, which is similar to the standard assert macro defined in <cassert>, but with an additional macro parameter supplying an error message. The macro is intended to be used in both Boost libraries and user code.
BOOST_ASSERT_MSG(expr, msg) is equivalent to
((void)0) if BOOST_DISABLE_ASSERTS or NDEBUG are
defined or expr evaluates to true. If those
macros and BOOST_ENABLE_ASSERT_HANDLER are not
defined, and expr evaluates to false, an error
message that includes #expr, msg, BOOST_CURRENT_FUNCTION,
__FILE__, and __LINE__ is sent to output stream
BOOST_ASSERT_MSG_OSTREAM
and std::abort() is called.
BOOST_ASSERT_MSG_OSTREAM defines the output stream. It defaults to std::cerr.
Integrated development environments (IDE's) like Microsoft Visual Studio
may produce easier to understand output if messages go to a different
stream, such as std::cout. Users may define BOOST_ASSERT_MSG_OSTREAM before including <boost/assert.hpp>
to specify a different output stream.
If the macro BOOST_ENABLE_ASSERT_HANDLER is defined when <boost/assert.hpp> is included, instead of sending a error message to an output stream, this expression is evaluated
::boost::assertion_failed_msg(#expr, msg, BOOST_CURRENT_FUNCTION, __FILE__, __LINE__)
assertion_failed_msg is declared in <boost/assert.hpp> as
namespace boost
{
void assertion_failed_msg(char const * expr, char const * msg, char const * function, char const * file, long line);
}
but it is never defined. The user is expected to supply an appropriate definition.
As is the case with <cassert>, <boost/assert.hpp> can be included multiple times in a single translation unit. BOOST_ASSERT_MSG will be redefined each time as specified above.
<boost/assert.hpp> also defines the macro BOOST_VERIFY. It has exactly the same behavior as BOOST_ASSERT, except that the expression that is passed to BOOST_VERIFY is always evaluated. This is useful when the asserted expression has desirable side effects; it can also help suppress warnings about unused variables when the only use of the variable is inside an assertion.
Copyright © 2002, 2007 by Peter Dimov. Copyright © 2011
by Beman Dawes. Distributed under the Boost Software
License, Version 1.0. See accompanying file LICENSE_1_0.txt
or copy at http://www.boost.org/LICENSE_1_0.txt.