Re: Templates and function parametes

[Rikki Cattermole via Digitalmars-d-learn]

On 9/08/2014 6:19 p.m., Paul D Anderson wrote:
When I try to compile these two functions, the second function is
flagged with an already defined error:
bool testRoundTrip(T, U)(T first, U second) if (isIntegral!T &&
isFloatingPoint!U)
{
     return false;
}
bool testRoundTrip(U, T)(U first, T second) if (isIntegral!T &&
isFloatingPoint!U)
{
     return false;
}

They look to me to be distinct functions, one with an integral parameter
followed by a floating point parameter and the other with a floating
point parameter followed by an integral parameter.

At first I thought this was a template problem, but the following code
also raises the same error.

bool testRoundTrip(int first, double second)
{
     return false;
}
bool testRoundTrip(double first, int second)
{
     return false;
}

What's the problem?

Cannot reproduce on either 2.065 or git head (according to dpaste).

import std.traits;

bool testRoundTrip(T, U)(T first, U second) if (isIntegral!T && 
isFloatingPoint!U)
{
    return first == 1;
}
bool testRoundTrip(U, T)(U first, T second) if (isIntegral!T && 
isFloatingPoint!U)
{
    return second == 2;
}

void main(){
        int x = 1;
        double y = 1.1;
        assert(testRoundTrip(x, y));
        
        x = 2;
        y = 2.2;
        assert(testRoundTrip(y, x));
        
        assert(testRoundTrip(1, 1.1));
        assert(testRoundTrip(2.2, 2));
}