2 replies to this topic

[TCristoforo]

Let's say I have to evaluate multiple types of conditions

if(A > B), if(A >= B)

and the opposites

if(A < B), if(A <= B)

Is there a way in C++ to pass the relational operators as parameters themselves, so that I might be able to have a function that looks something like the following

function name (argument B) <---this is not a bool value
{
if(B)
{
//run code here
}
}

[WingedPanther]

The Boost library has some support for passing strings that represent an expression.

[julmuri]

Sounds like you could use function objects.

#include <functional>


template < class Pred >
void foo( int a, int b, Pred pred )
{
    bool result = pred( a, b );

    if ( result )
    {
        //
        // run code
    } // if    
}

int main( int argc, char* argv[] )
{
    int a = 0, b = 1;

    //
    // run code if a < b
    foo( a, b, std::less<int>() );

    //
    // run code if a > b
    foo( a, b, std::greater<int>() );

    return 0;
}

Functional defines some generic ones, but you can create your own if need be.