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：

1. (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

1. namespace boost
2. {
3. void assertion_failed(charconst* expr,charconst* function,charconst* file,long line);
4. }

 

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

1. namespace boost
2. {
3. void assertion_failed_msg(charconst* expr,charconst* msg,charconst* function,charconst* file,long line);
4. }

 

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.