How to avoid throwing an exceptions for a built-in function?

[H. S. Teoh via Digitalmars-d-learn]

On Thu, May 11, 2017 at 05:55:03PM +0000, k-five via Digitalmars-d-learn wrote:
> On Thursday, 11 May 2017 at 17:18:37 UTC, crimaniak wrote:
> > On Wednesday, 10 May 2017 at 12:40:41 UTC, k-five wrote:
> ---------------------------------------------------------
> > try this:
> > https://dlang.org/phobos/std_exception.html#ifThrown
> 
> 
> 
> Worked. Thanks.
> 
> import std.stdio;
> import std.conv: to;
> import std.exception: ifThrown;
> 
> void main( string[] args ){
> 	
> 	string str = "string";
> 	int index = to!int( str ).ifThrown( 0 ); // if an exception was thrown, it
> is ignored and then return ( 0 );
> 	writeln( "index: ", index );	// 0
> }

Keep in mind, though, that you should not do this in an inner loop if
you care about performance, as throwing / catching exceptions will incur
a performance hit.  Outside of inner loops, though, it probably doesn't
matter.


T

-- 
Ph.D. = Permanent head Damage