• ref2401 (37/37) Mar 29 2016 OS: Win 8.1 Pro
• =?UTF-8?Q?Ali_=c3=87ehreli?= (9/13) Mar 29 2016 So, dict is a template value parameter of type T[string]. I don't think
• ref2401 (2/13) Mar 29 2016 alias works for me, thank you.
• ref2401 (9/12) Mar 30 2016 Found this in D language reference:

ref2401 <refactor24 gmail.com> writes:

OS: Win 8.1 Pro
DMD: v2.070.0
cmd: dmd main.d -ofconsole-app.exe -debug -unittest -wi

Code is successfully compiled until I uncomment test1 function 
call in the main.
If it's uncommented I get the following compile-time error:

main.d(58): Error: template instance impl!(string, bool, 
["y":true, "n":false]) does not match template declaration 
impl(S, T, Color[string] dict)(S arg)
main.d(62): Error: template instance mainentry.test1!string error 
instantiating

What have I done wrong?
Thank you.

import std.stdio;

enum Color { RED, GREEN }

private void impl(S, T, T[string] dict)(S arg) {
	writeln("S: ", S.stringof);
	writeln("T: ", T.stringof);
	writeln("dict: ", dict);
}

unittest {
	enum COLOR_MAP = [
		"r": Color.RED,
		"g": Color.GREEN
	];

	void test0(S)(S arg) {
		impl!(S, Color, COLOR_MAP)(arg);
	}

	test0("000");
}

void test1(S)(S arg) {
	impl!(S, bool, ["y": true, "n": false])(arg);
}

void main(string[] args) {
	// test1("111"); // if you uncomment this line you'll get a 
compile-time error
}

=?UTF-8?Q?Ali_=c3=87ehreli?= <acehreli yahoo.com> writes:

On 03/29/2016 11:21 AM, ref2401 wrote:

 private void impl(S, T, T[string] dict)(S arg) {
      writeln("S: ", S.stringof);
      writeln("T: ", T.stringof);
      writeln("dict: ", dict);

So, dict is a template value parameter of type T[string]. I don't think 
you can use an associative array as a template value parameter. (Can we?)

However, it is possible to use anything as an alias template parameter.

If it's acceptable in your case, the following works:

private void impl(S, T, alias dict)(S arg)
         if (is (typeof(dict) == T[S])) {

(Or T[string]).

Ali

ref2401 <refactor24 gmail.com> writes:

On Tuesday, 29 March 2016 at 18:29:27 UTC, Ali Çehreli wrote:
 On 03/29/2016 11:21 AM, ref2401 wrote:

 So, dict is a template value parameter of type T[string]. I 
 don't think you can use an associative array as a template 
 value parameter. (Can we?)

 However, it is possible to use anything as an alias template 
 parameter.

 If it's acceptable in your case, the following works:

 private void impl(S, T, alias dict)(S arg)
         if (is (typeof(dict) == T[S])) {

 (Or T[string]).

 Ali

alias works for me, thank you.

ref2401 <refactor24 gmail.com> writes:

On Tuesday, 29 March 2016 at 18:29:27 UTC, Ali Çehreli wrote:
 So, dict is a template value parameter of type T[string]. I 
 don't think you can use an associative array as a template 
 value parameter. (Can we?)

Found this in D language reference:
https://dlang.org/spec/template.html#template_value_parameter
Template value arguments can be integer values, floating point 
values, nulls, string values,
array literals of template value arguments, associative array 
literals of template value arguments...

So yes, associative arrays as template parameters are supposed to 
work.