In a template I need both the name and type of a given variable, but I have found a problem that can be shown with this simple code:

template Bar(string name) {
    pragma(msg, name);
}
template Foo(alias A) {
    alias Bar!(A.stringof) Foo;
}
void main() {
    int x = 10;
    alias Foo!(x) Nothing;
}

I'd like this code to print "x" instead of "int". Is this a bug of DMD V.1.033?

(At the moment I have solved the problem giving the template the name of the variable, and then finding its type with typeof(mixin("name")), but it's a less elegant solution).

Bye,
bearophile

"bearophile" <bearophileHUGS@lycos.com> wrote in message news:g5vi9l$1eok$1@digitalmars.com...
> In a template I need both the name and type of a given variable, but I have found a problem that can be shown with this simple code:
>
> template Bar(string name) {
>    pragma(msg, name);
> }
> template Foo(alias A) {
>    alias Bar!(A.stringof) Foo;
> }
> void main() {
>    int x = 10;
>    alias Foo!(x) Nothing;
> }
>
> I'd like this code to print "x" instead of "int". Is this a bug of DMD V.1.033?
>
> (At the moment I have solved the problem giving the template the name of the variable, and then finding its type with typeof(mixin("name")), but it's a less elegant solution).

It's got to be a bug.  If you put "pragma(msg, A.stringof);" in Foo, you'll notice it prints x and not int.  A workaround is, in Foo, to assign A.stringof to a constant and then pass that constant as the template argument to Bar.

bearophile wrote:
> In a template I need both the name and type of a given variable, but I have found a problem that can be shown with this simple code:
> 
> template Bar(string name) {
>     pragma(msg, name);
> }
> template Foo(alias A) {
>     alias Bar!(A.stringof) Foo;
> }
> void main() {
>     int x = 10;
>     alias Foo!(x) Nothing;
> }
> 
> I'd like this code to print "x" instead of "int". Is this a bug of DMD V.1.033?
> 
> (At the moment I have solved the problem giving the template the name of the variable, and then finding its type with typeof(mixin("name")), but it's a less elegant solution).
> 
> Bye,
> bearophile

I imagine once x gets into the template all the compiler knows about it is its type.

-Joel

"JAnderson" <ask@me.com> wrote in message news:g6286p$20q$1@digitalmars.com...
> bearophile wrote:
>> In a template I need both the name and type of a given variable, but I have found a problem that can be shown with this simple code:
>>
>> template Bar(string name) {
>>     pragma(msg, name);
>> }
>> template Foo(alias A) {
>>     alias Bar!(A.stringof) Foo;
>> }
>> void main() {
>>     int x = 10;
>>     alias Foo!(x) Nothing;
>> }
>>
>> I'd like this code to print "x" instead of "int". Is this a bug of DMD V.1.033?
>>
>> (At the moment I have solved the problem giving the template the name of the variable, and then finding its type with typeof(mixin("name")), but it's a less elegant solution).
>>
>> Bye,
>> bearophile
>
> I imagine once x gets into the template all the compiler knows about it is its type.

See my post.

bearophile wrote:
> In a template I need both the name and type of a given variable, but I have found a problem that can be shown with this simple code:
> 
> template Bar(string name) {
>     pragma(msg, name);
> }
> template Foo(alias A) {
>     alias Bar!(A.stringof) Foo;
> }
> void main() {
>     int x = 10;
>     alias Foo!(x) Nothing;
> }
> 
> I'd like this code to print "x" instead of "int". Is this a bug of DMD V.1.033?
> 
> (At the moment I have solved the problem giving the template the name of the variable, and then finding its type with typeof(mixin("name")), but it's a less elegant solution).
> 
> Bye,
> bearophile

A bug. Workaround:

template Foo(alias A) {
    alias Bar!(A.stringof ~ "") Foo;
}

Don:
> A bug. Workaround:
> template Foo(alias A) {
>      alias Bar!(A.stringof ~ "") Foo;
> }

Thank you, this workaround is very short and usable, it avoids me to use another template :-)

Bye,
bearophile