• "bearophile" <bearophileHUGS lycos.com> Nov 29 2012
• "Jonathan M Davis" <jmdavisProg gmx.com> Nov 29 2012
• "bearophile" <bearophileHUGS lycos.com> Nov 29 2012

"bearophile" <bearophileHUGS lycos.com> writes:

I have used std.algorithm.canFind with different tuple types by 
mistake, and the compiler has not complained. So to show it I 
have written some reduced code that uses just numbers:


import std.algorithm: canFind;
void main() {
     int[] arr1 = [1, 2];
     double x1 = 2.0;
     assert(arr1.canFind(x1));
     double[] arr2 = [1.0, 2.0];
     int x2 = 2;
     assert(arr2.canFind(x2));
}


Are both of those canFind calls acceptable?

Bye,
bearophile

"Jonathan M Davis" <jmdavisProg gmx.com> writes:

On Thursday, November 29, 2012 15:28:56 bearophile wrote:
 I have used std.algorithm.canFind with different tuple types by
 mistake, and the compiler has not complained. So to show it I
 have written some reduced code that uses just numbers:
 
 
 import std.algorithm: canFind;
 void main() {
 int[] arr1 = [1, 2];
 double x1 = 2.0;
 assert(arr1.canFind(x1));
 double[] arr2 = [1.0, 2.0];
 int x2 = 2;
 assert(arr2.canFind(x2));
 }
 
 
 Are both of those canFind calls acceptable?


Why wouldn't they be? You can compare int and double, and that's what find and 
canFind care about.

- Jonathan M Davis

"bearophile" <bearophileHUGS lycos.com> writes:

Jonathan M Davis:

 Why wouldn't they be? You can compare int and double, and 
 that's what find and canFind care about.


Right, it's a matter of equality operator.

In my code I was performing canFind on an array of tuples. So I 
didn't realize that the following code (where both tuple field 
type and field name are different) is accepted in D (probably I 
am getting used to the higher type strictness of functional 
languages):


import std.typecons: Tuple;
alias T1 = Tuple!(int, "x");
alias T2 = Tuple!(double, "y");
void main(string[] args) {
     assert(T1(1) == T2(1));
}


Bye,
bearophile