Getting N messages for N template parameter variations on a template.

void foo(A,B)();

A and B are selected from N different values and all are used.

If there is an error in the function then I get N^2 error messages, one for each combination. All the error messages say the same thing except A and B are different.

If the error message is several lines then that is multiplied by N^2.

Why can't D do a bit of error diagnostics. If the errors pertain to the same template and have every character the sample except the template values then just make a generic message:

These are the actual error messages, I did not copy and paste!!!



o.d(152): Error: function `foo!(float, float).bar(string)` is not callable using argument types `(int)`
o.d(152):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
o.d(174): Error: function `foo!(float, float).bar(string)` is not callable using argument types `(int)`
o.d(174):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
o.d-mixin-264(274): Error: template instance `foo!(float, float)` error instantiating
o.d(152): Error: function `foo!(float, int).bar(string)` is not callable using argument types `(int)`
o.d(152):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
o.d(174): Error: function `foo!(float, int).bar(string)` is not callable using argument types `(int)`
o.d(174):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
o.d-mixin-264(277): Error: template instance `foo!(float, int)` error instantiating
o.d(152): Error: function `foo!(float, int24).bar(string)` is not callable using argument types `(int)`
o.d(152):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
o.d(174): Error: function `foo!(float, int24).bar(string)` is not callable using argument types `(int)`
o.d(174):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
o.d-mixin-264(280): Error: template instance `foo!(float, int24)` error instantiating
o.d(152): Error: function `foo!(float, short).bar(string)` is not callable using argument types `(int)`
o.d(152):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
o.d(174): Error: function `foo!(float, short).bar(string)` is not callable using argument types `(int)`
o.d(174):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
o.d-mixin-264(283): Error: template instance `foo!(float, short)` error instantiating
o.d(152): Error: function `foo!(float, byte).bar(string)` is not callable using argument types `(int)`
o.d(152):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
o.d(174): Error: function `foo!(float, byte).bar(string)` is not callable using argument types `(int)`
o.d(174):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
o.d-mixin-264(286): Error: template instance `foo!(float, byte)` error instantiating
o.d(152): Error: function `foo!(float, ubyte).bar(string)` is not callable using argument types `(int)`
o.d(152):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
o.d(174): Error: function `foo!(float, ubyte).bar(string)` is not callable using argument types `(int)`
o.d(174):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
o.d-mixin-264(289): Error: template instance `foo!(float, ubyte)` error instantiating
o.d(152): Error: function `foo!(float, void).bar(string)` is not callable using argument types `(int)`
o.d(152):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
o.d(174): Error: function `foo!(float, void).bar(string)` is not callable using argument types `(int)`


and this is when A is constant!  When I allow A to vary then it is squared in number!! It is ridiculous!


It all could be simplified:

.d-mixin-264(274): Error: template instance `foo!(A, B)` error instantiating
o.d(152): Error: function `foo!(A, B).bar(string)` is not callable using argument types `(int)`
o.d(152):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
o.d(174): Error: function `foo!(A, B).bar(string)` is not callable using argument types `(int)`
o.d(174):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
where A is float, B is ubyte, void, float, etc...

On Saturday, 2 June 2018 at 09:48:26 UTC, IntegratedDimensions wrote:
> Getting N messages for N template parameter variations on a template.
>
> void foo(A,B)();
>
> A and B are selected from N different values and all are used.
>
> If there is an error in the function then I get N^2 error messages, one for each combination. All the error messages say the same thing except A and B are different.
>
> If the error message is several lines then that is multiplied by N^2.
>
> Why can't D do a bit of error diagnostics. If the errors pertain to the same template and have every character the sample except the template values then just make a generic message:
>
> These are the actual error messages, I did not copy and paste!!!
>
>
>
> o.d(152): Error: function `foo!(float, float).bar(string)` is not callable using argument types `(int)`
> o.d(152):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
> o.d(174): Error: function `foo!(float, float).bar(string)` is not callable using argument types `(int)`
> o.d(174):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
> o.d-mixin-264(274): Error: template instance `foo!(float, float)` error instantiating
> o.d(152): Error: function `foo!(float, int).bar(string)` is not callable using argument types `(int)`
> o.d(152):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
> o.d(174): Error: function `foo!(float, int).bar(string)` is not callable using argument types `(int)`
> o.d(174):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
> o.d-mixin-264(277): Error: template instance `foo!(float, int)` error instantiating
> o.d(152): Error: function `foo!(float, int24).bar(string)` is not callable using argument types `(int)`
> o.d(152):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
> o.d(174): Error: function `foo!(float, int24).bar(string)` is not callable using argument types `(int)`
> o.d(174):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
> o.d-mixin-264(280): Error: template instance `foo!(float, int24)` error instantiating
> o.d(152): Error: function `foo!(float, short).bar(string)` is not callable using argument types `(int)`
> o.d(152):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
> o.d(174): Error: function `foo!(float, short).bar(string)` is not callable using argument types `(int)`
> o.d(174):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
> o.d-mixin-264(283): Error: template instance `foo!(float, short)` error instantiating
> o.d(152): Error: function `foo!(float, byte).bar(string)` is not callable using argument types `(int)`
> o.d(152):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
> o.d(174): Error: function `foo!(float, byte).bar(string)` is not callable using argument types `(int)`
> o.d(174):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
> o.d-mixin-264(286): Error: template instance `foo!(float, byte)` error instantiating
> o.d(152): Error: function `foo!(float, ubyte).bar(string)` is not callable using argument types `(int)`
> o.d(152):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
> o.d(174): Error: function `foo!(float, ubyte).bar(string)` is not callable using argument types `(int)`
> o.d(174):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
> o.d-mixin-264(289): Error: template instance `foo!(float, ubyte)` error instantiating
> o.d(152): Error: function `foo!(float, void).bar(string)` is not callable using argument types `(int)`
> o.d(152):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
> o.d(174): Error: function `foo!(float, void).bar(string)` is not callable using argument types `(int)`
>
>
> and this is when A is constant!  When I allow A to vary then it is squared in number!! It is ridiculous!
>
>
> It all could be simplified:
>
> .d-mixin-264(274): Error: template instance `foo!(A, B)` error instantiating
> o.d(152): Error: function `foo!(A, B).bar(string)` is not callable using argument types `(int)`
> o.d(152):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
> o.d(174): Error: function `foo!(A, B).bar(string)` is not callable using argument types `(int)`
> o.d(174):        cannot pass argument `bufPos` of type `double` to parameter `int x = 0`
> where A is float, B is ubyte, void, float, etc...

Error messages like these are why language designers generally do not go the C++/D style template route, but instead do some limited meta programming, like with generics.