On 7/22/22 8:33 AM, Anthony Quizon wrote:
Hello,
I'm trying to create a mixin for quick binary operator overloads by
passing in types with a corresponding associative array of strings to
functions. However,
the code I currently have:
```
module foo;
mixin template opBi(
A, A function(A, A)[string] f0,
) {
static foreach (k, f; f0) { A opBinary(string op: k)(A r) { return
f(this, r); } }
}
struct A {
mixin opBi!(
A, [ "+": (A a, A b) => a],
);
}
struct B {
mixin opBi!(
B, [ "+": (B a, B b) => a],
);
}
```
Will not let me override operators on both struct A and B.
I get:
```
foo.d(16): Error: mixin `foo.B.opBi!(B, ["+":function (B a, B b) pure
nothrow @nogc @safe => a])` does not match template declaration `opBi(A,
A function(A, A)[string] f0)`
```
Is this a bug or am I doing something wrong?
It's typing the AA differently, and therefore it doesn't fit. The type
of the AA you are passing in is `T1[string]`, where it's expecting
`T2[string]`, where:
`T1` is `B function(B, B) pure nothrow @nogc @safe`
`T2` is `B function(B, B)`
I don't know if there's a better way to do this, other than use a
further template parameter to match the function type passed in.
-Steve
