• Ellery Newcomer (7/7) Apr 01 2010 this is going to be a bit of a nebulous question, but
• BCS (6/16) Apr 01 2010 some combination of "is()" "typeof" and "mixin()" should do it.
• Ellery Newcomer (27/41) Apr 03 2010 All right, here's a first try:
• BCS (8/10) Apr 03 2010 OK, lets try a slightly different question:

Ellery Newcomer <ellery-newcomer utulsa.edu> writes:

this is going to be a bit of a nebulous question, but

if I define a template

template T(string s){
}

where s is an identifier, then is there a good way to branch T's 
behavior based on whether s is declared in the scope in which T gets 
instantiated?

BCS <none anon.com> writes:

Hello Ellery,

 this is going to be a bit of a nebulous question, but
 
 if I define a template
 
 template T(string s){
 }
 where s is an identifier, then is there a good way to branch T's
 behavior based on whether s is declared in the scope in which T gets
 instantiated?
 

some combination of "is()" "typeof" and "mixin()" should do it.

//untested

static if( mixin("is("~s~")") ) { ... }

-- 
... <IXOYE><

Ellery Newcomer <ellery-newcomer utulsa.edu> writes:

On 04/01/2010 12:38 PM, BCS wrote:
 Hello Ellery,

 this is going to be a bit of a nebulous question, but

 if I define a template

 template T(string s){
 }
 where s is an identifier, then is there a good way to branch T's
 behavior based on whether s is declared in the scope in which T gets
 instantiated?

 some combination of "is()" "typeof" and "mixin()" should do it.

 //untested

 static if( mixin("is("~s~")") ) { ... }

All right, here's a first try:

//// test.d
module test;
import tok;

int a; //1
void main(){
     int a; //2
     void dummy(){};
     mixin T!("a");
}


//// tok.d
module tok;

int a; //3
template T(char[] k){
         static if (is(typeof(mixin(k)))){
             pragma(msg,"true");
             static if(is(typeof(mixin("."~k)))){
                 pragma(msg,"uh oh");
             }
             const K = true;
         }else{
             pragma(msg,"false");
             const K = false;
         }
}


The problem I see is it can't distinguish between 1 or 2 and 3

BCS <none anon.com> writes:

Hello Ellery,

 The problem I see is it can't distinguish between 1 or 2 and 3
 

OK, lets try a slightly different question:

Can code statically branch on what scope some symbol is in?

I'd look at __traits but I don't know how to do this off hand.

Being in a template mixin and getting passed in as a string just confuse 
the issue.

-- 
... <IXOYE><