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

[k-five via Digitalmars-d-learn]

On Wednesday, 10 May 2017 at 14:27:46 UTC, Stanislav Blinov wrote:
> On Wednesday, 10 May 2017 at 13:27:17 UTC, k-five wrote:
>
>> Thanks, but I know about what are you saying. The 
>> user_apply[4] has so many possibilities and I cannot use 
>> if-else
>
> That doesn't sound right. Either you've already handled all the 
> possible cases and thus expect the to! to not throw (can 
> specify that i.e. via std.exception.assumeWontThrow), or, as 
> you're saying, it's much more than an if-else, but in that case 
> exception will be thrown on invalid input.

------------------------------------------------------------------

I know. But I am saying that I do not want to take care of any 
exceptions.
I just wanted to write:

int variable = to!int( string-type );

In fact something like using "no throw" is a function:
void init( ... ) nothrow {
     ...
     int variable = to!int( string-type );
     ...
}

but this is not valid.

Thanks anyway and I will test: Function 
std.exception.assumeWontThrow at this link:
https://dlang.org/library/std/exception/assume_wont_throw.html