id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
12001,"Under C++11, BOOST_TEST() wrong on boost::optional + named-parameter-idiom example",Tony Lewis <tonyelewis@…>,Gennadiy Rozental,"The example below shows the `BOOST_TEST()` assertions failing where they should pass, as the equivalent `BOOST_CHECK_EQUAL()` assertions do. It looks as though `BOOST_TEST()` is preventing the named-parameter-idiom setter from changing the `optional` value from `boost::none`.

Importantly, this code works if compiled without `-std=c++11`.

Compile commands:

{{{
g++ -std=c++11 -isystem $BOOST_ROOT/include test_test_bug.cpp -L$BOOST_ROOT/lib -lboost_unit_test_framework-mt
setenv LD_LIBRARY_PATH $BOOST_ROOT/lib
./a.out -l all
}}}

Code:

{{{
#!cpp
#ifndef BOOST_TEST_DYN_LINK
#define BOOST_TEST_DYN_LINK
#endif
#include <boost/test/unit_test.hpp>

#include <boost/optional/optional.hpp>
#include <boost/optional/optional_io.hpp>

#include <iostream>

class my_class {
private:
	boost::optional<int> num;

public:
	my_class(const boost::optional<int> &arg_num) : num ( arg_num ) {}

	const boost::optional<int> & get_num() const {
		return num;
	}

	const my_class & set_num(const boost::optional<int> &arg_num) {
		num = arg_num;
		return *this;
	}
};

// Simple stream insertion operator
std::ostream & operator<<(std::ostream &os, const my_class &my_obj) {
	os << ""my_class[ "" << my_obj.get_num() << "" ]"";
	return os;
}

// Simple equality predicate operator
bool operator==(const my_class &my_obj_a, const my_class &my_obj_b) {
	return ( my_obj_a.get_num() == my_obj_b.get_num() );
}

BOOST_AUTO_TEST_CASE(my_test) {
	const my_class correct_answer( 5 );

	// These two work as expected
	BOOST_CHECK_EQUAL( my_class( boost::none ).set_num( 5 ),   correct_answer                       );
	BOOST_CHECK_EQUAL( correct_answer,                         my_class( boost::none ).set_num( 5 ) );

	// These two fail, evaluating the non-trivial side as ""my_class[ -- ]""
	BOOST_TEST       ( my_class( boost::none ).set_num( 5 ) == correct_answer                       );
	BOOST_TEST       ( correct_answer                       == my_class( boost::none ).set_num( 5 ) );
}

bool init_function() { return true; }
int main( int argc, char* argv[] ) {
    return ::boost::unit_test::unit_test_main( &init_function, argc, argv );
}

}}}",Bugs,closed,To Be Determined,test,Boost 1.60.0,Problem,obsolete,"test,optional,BOOST_TEST,BOOST_CHECK_EQUAL,c++11,named parameter idiom",