template<typename Fn, typename ReverseLeft, typename ReverseRight>

minilua::BinaryNumericFunctionHelper struct

Helper for creating a reversible numeric binary function.

With this helper you don't have to manually match the Values you just have to provide functions that take Number values and return Number values for:

1. the normal function you want to write
2. the reverse function for propagating the changed result to the left parameter
3. the reverse function for propagating the changed result to the right parameter

Usage (using the deduction guide):

function pow_impl(const CallContext& ctx) -> Value {
    return minilua::BinaryNumericFunctionHelper{
        [](Number lhs, Number rhs) { return std::pow(lhs.as_float(), rhs.as_float()); },
        [](Number new_value, Number old_rhs) { return std::pow(new_value.as_float(), 1 /
old_rhs.as_float()); },
        [](Number new_value, Number old_lhs) { return std::log(new_value.as_float()) /
std::log(old_lhs.as_float()); }
     }(ctx);
}

Note the call at the end.

It's also possible to directly use the BinaryNumericFunctionHelper as the argument to Function because it is callable with a CallContext argument.

See also: UnaryNumericFunctionHelper.