opEquals nothrow

[Steven Schveighoffer via Digitalmars-d-learn]

On 7/20/17 11:10 AM, Aldo wrote:
> On Thursday, 20 July 2017 at 14:59:50 UTC, Steven Schveighoffer wrote:
>> On 7/20/17 10:38 AM, Aldo wrote:
>>> Hello,
>>>
>>> im tring to add nothrow keyword in my code, but compilation fails :
>>>
>>> function 'object.opEquals' is not nothrow
>>>
>>>
>>> its a simple comparison between 2 objects. How to make opEquals 
>>> nothrow ?
>>
>> You can't. Object.opEquals is not nothrow, so object.opEquals is not 
>> nothrow (note the former is the virtual member function, the latter is 
>> a global function which is what the compiler actually calls).
>>
>> It is a legacy limitation. Until we get rid of all the Object base 
>> methods for things like opEquals and toHash, we will not be able to 
>> fix this.
>>
> 
> Im using DerelictGLFW3, to process events im doing this :
> 
> glfwSetMouseButtonCallback(window, &onMouseClick);
> 
> onMouseClick function must be nothrow.
> 
> But now I can't do anything in this function because I can't convert my 
> code to nothrow.
> 
> Can I put a try catch in the body ?

Yes.

> 
> extern(C) nothrow
> {
>      void onMouseClick(GLFWwindow* window, int button, int action, int d)
>      {
>         try
>         {
>             // my code
>         }
>         catch
>         {
> 
>         }
>      }
> }
> 
> it seems its working but what about performances ?

As long as you don't have any code that throws, it should be pretty 
close to optimal.

-Steve