On 01/19/2016 03:37 PM, QAston wrote:
Hi,
I have the following code:
auto appendMapped(alias f, R, T)(R r, T elem) {
r ~= f(elem);
return r;
}
int minus(int i) {
return -i;
}
unittest {
int[] ar;
// here I do partial application of minus function
alias appendMinus(S,T) = appendMapped!(minus, S, T);
assert (appendMinus!(int[], int)(ar, 10) == [-10]); // compiles
assert (appendMinus(ar, 10) == [-10]); // doesn't compile
}
Which gives me following error:
Error: template transduced.__unittestL111_2.appendMinus cannot deduce
function from argument types !()(int[], int), candidates are:
transduced.__unittestL111_2.appendMinus(S, T)
Is there a way to do partial template arg application which does
template type deduction correctly?
I don't know whether it's possible with 'alias' but the following
trivial wrapper works:
auto appendMinus(S,T)(S s, T t) {
return appendMapped!minus(s, t);
}
Ali