Example

The following example illustrates different approaches you can employ to detect and report errors using different testing tools

Table 57. Minimal testing facility application

Code

Output

#include <boost/test/minimal.hpp>

//____________________________________________________________________________//

int add( int i, int j ) { return i+j; }

//____________________________________________________________________________//

int test_main( int, char *[] )             // note the name!
{
  // six ways to detect and report the same error:

  // continues on error
  BOOST_CHECK( add( 2,2 ) == 4 );  

  // throws on error
  BOOST_REQUIRE( add( 2,2 ) == 4 ); 

  // continues on error
  if( add( 2,2 ) != 4 )
    BOOST_ERROR( "Ouch..." );       

  // throws on error
  if( add( 2,2 ) != 4 )
    BOOST_FAIL( "Ouch..." );        

  // throws on error
  if( add( 2,2 ) != 4 )
    throw "Oops...";                

  // returns error code
  return add( 2, 2 ) == 4 ? 0 : 1;  
}

	This approach uses the `BOOST_CHECK` tool, which displays an error message on std::cout that includes the expression that failed, the source file name, and the source file line number. It also increments the error count. At program termination, the error count will be displayed automatically by the Minimal Testing Facility.
	This approach using the `BOOST_REQUIRE` tool, is similar to #1, except that after displaying the error, an exception is thrown, to be caught by the Minimal Testing Facility. This approach is suitable when writing an explicit test program, and the error would be so severe as to make further testing impractical. `BOOST_REQUIRE` differs from the C++ Standard Library's `assert()` macro in that it is always generated, and channels error detection into the uniform reporting procedure.
	This approach is similar to #1, except that the error detection is coded separately. This is most useful when the specific condition being tested is not indicative of the reason for failure.
	This approach is similar to #2, except that the error detection is coded separately. This is most useful when the specific condition being tested is not indicative of the reason for failure.
	This approach throws an exception, which will be caught and reported by the Minimal Testing Facility. This approach is suitable for both production and test code, in libraries or not. The error message displayed when the exception is caught will be most meaningful if the exception is derived from `std::exception`, or is a `char*` or `std::string`.
	An error code may be returned by the Minimal Testing Facility

**** no errors detected