Boost.Test ASSERT断言用法
使用文件
包含头文件即可:assert.hpp
主要就是5个断言:
BOOST_ASSERT
BOOST_ASSERT_MSG
BOOST_VERIFY
BOOST_VERIFY_MSG
BOOST_ASSERT_IS_VOID
官方文档:
BOOST_ASSERT
BOOST_ASSERT_MSG
BOOST_VERIFY
BOOST_VERIFY_MSG
BOOST_ASSERT_IS_VOID
BOOST_ASSERT
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.
头文件<boost/assert.hpp>定义了宏BOOST_ASSERT,它类似于中定义的标准断言宏。宏的目的是在Boost库和用户代码中使用。
这个宏,在定义了NDEBUG时,会被直接禁用掉
• By default, BOOST_ASSERT(expr) expands to assert(expr).
默认的,BOOST_ASSERT(expr) 会扩展成 assert(expr).
• If the macro BOOST_DISABLE_ASSERTS is defined when <boost/assert.hpp> is included, BOOST_ASSERT(expr) expands to ((void)0), regardless of whether the macro NDEBUG is defined. This allows users to selectively disable BOOST_ASSERT without affecting the definition of the standard assert.
如果在包含头文件 <boost/assert.hpp> 时,定义了宏boost_disable_assert, BOOST_ASSERT(expr)扩展到((void)0),不管是否定义了宏NDEBUG。这允许用户选择性地禁用BOOST_ASSERT,而不影响标准断言的定义。
• If the macro BOOST_ENABLE_ASSERT_HANDLER is defined when <boost/assert.hpp> is included, BOOST_ASSERT(expr) expands to
包含头文件<boost/assert.hpp>的时候,如果定义了宏:BOOST_ENABLE_ASSERT_HANDLER,
BOOST_ASSERT(expr)将会扩展为:
(BOOST_LIKELY(!!(expr))?((void)0):::boost::assertion_failed(#expr, BOOST_CURRENT_FUNCTION, __FILE__, __LINE__))
That is, it evaluates expr and if it's false, calls ::boost::assertion_failed(#expr, BOOST_CURRENT_FUNCTION, __FILE__, __LINE__). This is true regardless of whether NDEBUG is defined.
boost::assertion_failed is declared in <boost/assert.hpp> as
namespace boost{void assertion_failed(charconst* expr,charconst* function,charconst* file,long line);}
but it is never defined. The user is expected to supply an appropriate definition.
• If the macro BOOST_ENABLE_ASSERT_DEBUG_HANDLER is defined when <boost/assert.hpp> is included, BOOST_ASSERT(expr) expands to ((void)0) when NDEBUGis defined. Otherwise the behavior is as if BOOST_ENABLE_ASSERT_HANDLER has been defined.
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.
BOOST_ASSERT_MSG
The macro BOOST_ASSERT_MSG is similar to BOOST_ASSERT, but it takes an additional argument, a character literal, supplying an error message.
• By default, BOOST_ASSERT_MSG(expr,msg) expands to assert((expr)&&(msg)).
• If the macro BOOST_DISABLE_ASSERTS is defined when <boost/assert.hpp> is included, BOOST_ASSERT_MSG(expr,msg) expands to ((void)0), regardless of whether the macro NDEBUG is defined.
• If the macro BOOST_ENABLE_ASSERT_HANDLER is defined when <boost/assert.hpp> is included, BOOST_ASSERT_MSG(expr,msg) expands to
(BOOST_LIKELY(!!(expr))? ((void)0): ::boost::assertion_failed_msg(#expr, msg, BOOST_CURRENT_FUNCTION, __FILE__, __LINE__))
This is true regardless of whether NDEBUG is defined.
boost::assertion_failed_msg is declared in <boost/assert.hpp> as
namespace boost{void assertion_failed_msg(charconst* expr,charconst* msg,charconst* function,charconst* file,long line);}
but it is never defined. The user is expected to supply an appropriate definition.
• If the macro BOOST_ENABLE_ASSERT_DEBUG_HANDLER is defined when <boost/assert.hpp> is included, BOOST_ASSERT_MSG(expr) expands to ((void)0) when NDEBUG is defined. Otherwise the behavior is as if BOOST_ENABLE_ASSERT_HANDLER has been defined.
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_VERIFY
The macro BOOST_VERIFY has 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.
• If the macro BOOST_DISABLE_ASSERTS is defined when <boost/assert.hpp> is included, BOOST_VERIFY(expr) expands to ((void)(expr)).
• If the macro BOOST_ENABLE_ASSERT_HANDLER is defined when <boost/assert.hpp> is included, BOOST_VERIFY(expr) expands to BOOST_ASSERT(expr).
• Otherwise, BOOST_VERIFY(expr) expands to ((void)(expr)) when NDEBUG is defined, to BOOST_ASSERT(expr) when it's not.
BOOST_VERIFY_MSG
The macro BOOST_VERIFY_MSG is similar to BOOST_VERIFY, with an additional parameter, an error message.
• If the macro BOOST_DISABLE_ASSERTS is defined when <boost/assert.hpp> is included, BOOST_VERIFY_MSG(expr,msg) expands to ((void)(expr)).
• If the macro BOOST_ENABLE_ASSERT_HANDLER is defined when <boost/assert.hpp> is included, BOOST_VERIFY_MSG(expr,msg) expands to BOOST_ASSERT_MSG(expr,msg).
• Otherwise, BOOST_VERIFY_MSG(expr,msg) expands to ((void)(expr)) when NDEBUG is defined, to BOOST_ASSERT_MSG(expr,msg) when it's not.
BOOST_ASSERT_IS_VOID
The macro BOOST_ASSERT_IS_VOID is defined when BOOST_ASSERT and BOOST_ASSERT_MSG, are expanded to ((void)0). This macro is useful to avoid compiling and potentially running code that is only intended to prepare data to be used in the assertion.
void MyContainer::erase(iterator i)
{
//Some sanity checks, data must be ordered
#ifndef BOOST_ASSERT_IS_VOID
if(i != c.begin()){
iterator prev = i;
--prev;
BOOST_ASSERT(*prev < *i);
}
else if(i != c.end()){
iterator next = i;
++next;
BOOST_ASSERT(*i < *next);
}
#endif
this->erase_impl(i);
}
• By default, BOOST_ASSERT_IS_VOID is defined if NDEBUG is defined.
• If the macro BOOST_DISABLE_ASSERTS is defined BOOST_ASSERT_IS_VOID is always defined.
• If the macro BOOST_ENABLE_ASSERT_HANDLER is defined BOOST_ASSERT_IS_VOID is never defined.
• If the macro BOOST_ENABLE_ASSERT_DEBUG_HANDLER, then BOOST_ASSERT_IS_VOID is defined when NDEBUG is defined.

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