www.digitalmars.com         C & C++   DMDScript  

digitalmars.D - No TypeTuple expansion for assert?

reply =?UTF-8?B?QWxpIMOHZWhyZWxp?= <acehreli yahoo.com> writes:
I know that assert is not a function but it would be nice to have.

import std.exception;

void foo(T...)(T args)
{
     // Compiles:
     enforce(args);

     // DOES NOT COMPILE:
     // assert(args);

     // Must expand manually:
     assert(args[0], args[1]);
}

void main()
{
     foo(true, "hi");
}

Ali
Oct 03 2014
next sibling parent reply Dmitry Olshansky <dmitry.olsh gmail.com> writes:
03-Oct-2014 23:08, Ali Çehreli пишет:

 I know that assert is not a function but it would be nice to have.


Indeed. If we make it a function and put in object.d would anyone notice 
the change?


 import std.exception;

 void foo(T...)(T args)
 {
      // Compiles:
      enforce(args);

      // DOES NOT COMPILE:
      // assert(args);

      // Must expand manually:
      assert(args[0], args[1]);
 }

 void main()
 {
      foo(true, "hi");
 }

 Ali



-- 
Dmitry Olshansky
Oct 03 2014
parent reply "monarch_dodra" <monarchdodra gmail.com> writes:
On Friday, 3 October 2014 at 19:21:38 UTC, Dmitry Olshansky wrote:

 03-Oct-2014 23:08, Ali Çehreli пишет:

 I know that assert is not a function but it would be nice to 
 have.


 Indeed. If we make it a function and put in object.d would 
 anyone notice the change?


I think there are semantics that prevent that. Such as 
"assert(0)", or removing the evaluation of arg in "assert(arg())" 
altogether in release.
Oct 03 2014
parent reply "H. S. Teoh via Digitalmars-d" <digitalmars-d puremagic.com> writes:
On Fri, Oct 03, 2014 at 08:02:14PM +0000, monarch_dodra via Digitalmars-d wrote:

 On Friday, 3 October 2014 at 19:21:38 UTC, Dmitry Olshansky wrote:

03-Oct-2014 23:08, Ali Çehreli пишет:

I know that assert is not a function but it would be nice to have.


Indeed. If we make it a function and put in object.d would anyone
notice the change?


 
 I think there are semantics that prevent that. Such as "assert(0)", or
 removing the evaluation of arg in "assert(arg())" altogether in
 release.


	void assert(lazy bool exp) {
		version(assert) // (!)
			if (!exp) __fatal_runtime_error();
	}

Doesn't work for assert(0); but does work for not evaluating the
argument in release build. (Yeah I know, implementation of 'lazy' leaves
a lot to be desired, but hey, that can be argued to be a QOI issue.)


T

-- 
This is not a sentence.
Oct 03 2014
parent "monarch_dodra" <monarchdodra gmail.com> writes:
On Friday, 3 October 2014 at 20:28:21 UTC, H. S. Teoh via 
Digitalmars-d wrote:

 On Fri, Oct 03, 2014 at 08:02:14PM +0000, monarch_dodra via 
 Digitalmars-d wrote:

 On Friday, 3 October 2014 at 19:21:38 UTC, Dmitry Olshansky 
 wrote:

03-Oct-2014 23:08, Ali Çehreli пишет:

I know that assert is not a function but it would be nice to 
have.


Indeed. If we make it a function and put in object.d would 
anyone
notice the change?


 
 I think there are semantics that prevent that. Such as 
 "assert(0)", or
 removing the evaluation of arg in "assert(arg())" altogether in
 release.


 	void assert(lazy bool exp) {
 		version(assert) // (!)
 			if (!exp) __fatal_runtime_error();
 	}

 Doesn't work for assert(0); but does work for not evaluating the
 argument in release build. (Yeah I know, implementation of 
 'lazy' leaves
 a lot to be desired, but hey, that can be argued to be a QOI 
 issue.)


 T


There might still be an issue in regards to linking though: I 
have some code where assert-only functions are only defined for 
non-release.
Oct 04 2014
prev sibling parent Timon Gehr <timon.gehr gmx.ch> writes:
On 10/03/2014 09:08 PM, Ali Çehreli wrote:

 I know that assert is not a function but it would be nice to have.

 import std.exception;

 void foo(T...)(T args)
 {
      // Compiles:
      enforce(args);

      // DOES NOT COMPILE:
      // assert(args);

      // Must expand manually:
      assert(args[0], args[1]);
 }

 void main()
 {
      foo(true, "hi");
 }

 Ali


It should just auto-expand. There is no reason for it not to. Same for 
static assert.
Oct 04 2014