CODEWITHSUNDEEP
c++templatesconstantsc++14compile-time-constant
TheBojanovski
TheBojanovski

Reputation: 137

Branching out templated code based on a non const bool

This is the function I'm trying to simplify:

void BaseCharacter::ClimbLadder(float AxisValue)
{
    if (AxisValue > 0.f)
        ClimbUpLadder<bIsClimbingLaddersFast>();
    else if (AxisValue < 0.f)
        ClimbDownLadder<bIsClimbingLaddersFast>();
}

With bIsClimbingLaddersFast being a Boolean member variable. Now, the code doesn't compile because the value of the Boolean needs to be known in compile time. This is the trivial solution:

void BaseCharacter::ClimbLadder(float AxisValue)
{
    if (bIsClimbingLaddersFast)
    {
        if (AxisValue > 0.f)
            ClimbUpLadder<true>();
        else if (AxisValue < 0.f)
            ClimbDownLadder<true>();
    }
    else
    {
        if (AxisValue > 0.f)
            ClimbUpLadder<false>();
        else if (AxisValue < 0.f)
            ClimbDownLadder<false>();
    }
}

But I'm wondering if there is a cleaner way to write this, one without the duplicate if-else statements. C++14 is being used.

Upvotes: 0

Views: 90

Answers (1)

Surt
Surt

Reputation: 16089

A possible (totally untested code) solution.

template<bool climb>
void BaseCharacter::ClimbLadder(float AxisValue) {
    if (AxisValue > 0.f)
        ClimbUpLadder<climb>();
    else if (AxisValue < 0.f)
        ClimbDownLadder<climb>();
}

void BaseCharacter::ClimbLadder(float AxisValue) {
    if (bIsClimbingLaddersFast)
        ClimbLadder<true>(AxisValue);
    else
        ClimbLadder<false>(AxisValue);
}

Upvotes: 1

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