• albertas-jn (3/3) Dec 06 2018 If templates are a compile-time feature and instances of
• Basile B. (3/6) Dec 06 2018 Because to instantiate the source code is still used (-I). Just
• =?UTF-8?Q?Ali_=c3=87ehreli?= (21/24) Dec 06 2018 There is no trace of the template in the library or the object file. You...
• albertas-jn (7/26) Dec 06 2018 I see, what confused me was that if I put main() in a different
• Neia Neutuladh (5/8) Dec 06 2018 You compile files, not individual declarations like a template. If you

albertas-jn <adasf fsdk.com> writes:

If templates are a compile-time feature and instances of 
templates are generated by compiler at compile time, why is it 
possible to compile a template definition with dmd -lib or -c?

Basile B. <b2.temp gmx.com> writes:

On Thursday, 6 December 2018 at 22:50:49 UTC, albertas-jn wrote:
 If templates are a compile-time feature and instances of 
 templates are generated by compiler at compile time, why is it 
 possible to compile a template definition with dmd -lib or -c?

Because to instantiate the source code is still used (-I). Just 
the D interface is even not enough.

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

On 12/06/2018 02:50 PM, albertas-jn wrote:
 If templates are a compile-time feature and instances of templates are 
 generated by compiler at compile time, why is it possible to compile a 
 template definition with dmd -lib or -c?

There is no trace of the template in the library or the object file. You 
can investigate the compiled symbols with e.g. the 'nm' tool on Linux 
systems:

// deneme.d:
void foo(T)(T t) {
     import std.stdio;
     writeln(t);
}

void main() {
     // foo(42);
}

$ dmd deneme.d -lib
$ nm deneme.a | grep foo

No trace of foo... Now uncomment the line in main and repeat:

$ dmd deneme.d -lib
$ nm deneme.a | grep foo
                  U _D6deneme__T3fooTiZQhFNfiZv
0000000000000000 W _D6deneme__T3fooTiZQhFNfiZv

"W" indicates a definition.

Ali

albertas-jn <adasf fsdk.com> writes:

On Friday, 7 December 2018 at 01:21:42 UTC, Ali Çehreli wrote:

 There is no trace of the template in the library or the object 
 file. You can investigate the compiled symbols with e.g. the 
 'nm' tool on Linux systems:

 // deneme.d:
 void foo(T)(T t) {
     import std.stdio;
     writeln(t);
 }

 void main() {
     // foo(42);
 }

 $ dmd deneme.d -lib
 $ nm deneme.a | grep foo

 No trace of foo... Now uncomment the line in main and repeat:

 $ dmd deneme.d -lib
 $ nm deneme.a | grep foo
                  U _D6deneme__T3fooTiZQhFNfiZv
 0000000000000000 W _D6deneme__T3fooTiZQhFNfiZv

 "W" indicates a definition.

I see, what confused me was that if I put main() in a different 
file and

$ dmd main.d deneme.a

the program compiled properly. Now I realize that in this case 
deneme.a file was ignored and the source file was used instead. I 
expected an error. Thank you for your answers.

Neia Neutuladh <neia ikeran.org> writes:

On Thu, 06 Dec 2018 22:50:49 +0000, albertas-jn wrote:
 If templates are a compile-time feature and instances of templates are
 generated by compiler at compile time, why is it possible to compile a
 template definition with dmd -lib or -c?

You compile files, not individual declarations like a template. If you 
have a source file containing a hundred templates and nothing else, and 
you compile it, you'll get the same output as if you had an empty source 
file, byte for byte.