overload_mismatch.chr

:- module(overload_mismatch, [result/2]).
:- use_module(library(prelude)).

:- chr_constraint result(any, any).

:- chr_type color ---> red ; green ; blue.

% Overloaded function: works on int and string only
:- class
    (size(int) -> int),
    (size(string) -> int).

size(N) | integer(N) -> N.
size(S) | string(S) -> string_length(S).

% Type error: color is not a valid argument for size
:- chr_constraint foo(color).
foo(X) <=> R is size(X).