Hello,
This code doesn't print enum values:
>import std.meta;
>import std.traits;
>import std.stdio;
>
>enum MyEnum : string
>{
>    First = "F_i_r_s_t",
>    Second = "S_e_c_o_n_d"
>}
>
>alias QW(alias arg) = Alias!(cast(OriginalType!(typeof(arg)))arg);
>
>void print(T...)(T args)
>{
>    writeln(cast(OriginalType!(typeof(args[0])))args[0]); // Works...
>    writeln(QW!(args[0]));                                // Doesn't work... MUST!
> 
>    writeln(staticMap!(QW, args));                        // Doesn't work... MUST!
>}
>
>void main()
>{
>    bool runTimeBool = true;
>    print(MyEnum.First, 7, runTimeBool, MyEnum.Second);
>}

Must print "F_i_r_s_t" and "S_e_c_o_n_d", not just "First" and "Second".

On Thursday, 30 August 2018 at 10:41:58 UTC, Andrey wrote:
> Hello,
> This code doesn't print enum values:
>>import std.meta;
>>import std.traits;
>>import std.stdio;
>>
>>enum MyEnum : string
>>{
>>    First = "F_i_r_s_t",
>>    Second = "S_e_c_o_n_d"
>>}
>>
>>alias QW(alias arg) = Alias!(cast(OriginalType!(typeof(arg)))arg);
>>
>>void print(T...)(T args)
>>{
>>    writeln(cast(OriginalType!(typeof(args[0])))args[0]); // Works...
>>    writeln(QW!(args[0]));                                // Doesn't work... MUST!
>> 
>>    writeln(staticMap!(QW, args));                        // Doesn't work... MUST!
>>}
>>
>>void main()
>>{
>>    bool runTimeBool = true;
>>    print(MyEnum.First, 7, runTimeBool, MyEnum.Second);
>>}
>
> Must print "F_i_r_s_t" and "S_e_c_o_n_d", not just "First" and "Second".

args are runtime arguments.

import std.experimental.all;

enum MyEnum : string
{
    First = "F_i_r_s_t",
    Second = "S_e_c_o_n_d"
}

///alias QW(alias arg) = Alias!(cast(OriginalType!(typeof(arg)))arg);
auto QW(T)(const auto ref T x){
	return cast(OriginalType!T)x;
}

void print(T...)(T args)
{
    writeln(cast(OriginalType!(typeof(args[0])))args[0]); // Works...
    ///writeln(QW!(args[0]));                                // Doesn't work... MUST!
    writeln(QW(args[0]));

    static foreach(alias arg; args){
        static if(is(typeof(arg) : MyEnum))write(QW(arg));
    	else write(arg);
    }
    write('\n');
    //writeln(staticMap!(QW, args));                        // Doesn't work... MUST!
}

void main()
{
    bool runTimeBool = true;
    print(MyEnum.First, 7, runTimeBool, MyEnum.Second);
}

On Thursday, 30 August 2018 at 11:09:40 UTC, vit wrote:
> args are runtime arguments.
>
> import std.experimental.all;
>
> enum MyEnum : string
> {
>     First = "F_i_r_s_t",
>     Second = "S_e_c_o_n_d"
> }
>
> ///alias QW(alias arg) = Alias!(cast(OriginalType!(typeof(arg)))arg);
> auto QW(T)(const auto ref T x){
> 	return cast(OriginalType!T)x;
> }
>
> void print(T...)(T args)
> {
>     writeln(cast(OriginalType!(typeof(args[0])))args[0]); // Works...
>     ///writeln(QW!(args[0]));                                // Doesn't work... MUST!
>     writeln(QW(args[0]));
>
>     static foreach(alias arg; args){
>         static if(is(typeof(arg) : MyEnum))write(QW(arg));
>     	else write(arg);
>     }
>     write('\n');
>     //writeln(staticMap!(QW, args));                        // Doesn't work... MUST!
> }
>
> void main()
> {
>     bool runTimeBool = true;
>     print(MyEnum.First, 7, runTimeBool, MyEnum.Second);
> }

I want to create a reusable template for this purpose.
Why I can't use "staticMap" so that compiler it self would do this:
>void print(T...)(T args)
>{
>    writeln(cast(OriginalType!(typeof(args[0])))args[0], cast(OriginalType!(typeof(args[1])))args[1], cast(OriginalType!(typeof(args[2])))args[2], cast(OriginalType!(typeof(args[3])))args[3]);
>}
Just wrap some some symbol "args" with some expression at compile time.

It is the same as in C++:
>template<Args...>
>void print(Args ...args)
>{
>    writeln(UnderlyingType(args)...); // UnderlyingType is a function here
>}

On Thursday, 30 August 2018 at 11:34:36 UTC, Andrey wrote:
> On Thursday, 30 August 2018 at 11:09:40 UTC, vit wrote:
>> [...]
>
> I want to create a reusable template for this purpose.
> Why I can't use "staticMap" so that compiler it self would do this:
>>[...]
> Just wrap some some symbol "args" with some expression at compile time.
>
> It is the same as in C++:
>>[...]

D doesn't have expanding like C++

Unfortunately D has only simple automatic expading.

On Thursday, 30 August 2018 at 12:04:26 UTC, vit wrote:
> On Thursday, 30 August 2018 at 11:34:36 UTC, Andrey wrote:
>> On Thursday, 30 August 2018 at 11:09:40 UTC, vit wrote:
>>> [...]
>>
>> I want to create a reusable template for this purpose.
>> Why I can't use "staticMap" so that compiler it self would do this:
>>>[...]
>> Just wrap some some symbol "args" with some expression at compile time.
>>
>> It is the same as in C++:
>>>[...]
>
> D doesn't have expanding like C++
>
> Unfortunately D has only simple automatic expading.

So how can one implement a reusable template "apply some function to each argument in template parameter pack" in D?

On Friday, 31 August 2018 at 10:51:51 UTC, Andrey wrote:
> On Thursday, 30 August 2018 at 12:04:26 UTC, vit wrote:
>> On Thursday, 30 August 2018 at 11:34:36 UTC, Andrey wrote:
>>> On Thursday, 30 August 2018 at 11:09:40 UTC, vit wrote:
>>>> [...]
>>>
>>> I want to create a reusable template for this purpose.
>>> Why I can't use "staticMap" so that compiler it self would do this:
>>>>[...]
>>> Just wrap some some symbol "args" with some expression at compile time.
>>>
>>> It is the same as in C++:
>>>>[...]
>>
>> D doesn't have expanding like C++
>>
>> Unfortunately D has only simple automatic expading.
>
> So how can one implement a reusable template "apply some function to each argument in template parameter pack" in D?

auto ToUnderlyingType(alias a)() {
    return cast(OriginalType!(typeof(a)))a;
}

void print(T...)(T args) {
    writeln(staticMap!(ToUnderlyingType, args));
}

On Friday, 31 August 2018 at 12:21:48 UTC, aliak wrote:
> auto ToUnderlyingType(alias a)() {
>     return cast(OriginalType!(typeof(a)))a;
> }
>
> void print(T...)(T args) {
>     writeln(staticMap!(ToUnderlyingType, args));
> }


Oohhh. So easy! Killed 2 days - and templates and mixins tried... And the solution was to use TEMPLATE function with alias not regular...
Thank you!