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digitalmars.D.learn - Two functions with different args. Taking address of the one

reply =?UTF-8?B?0JLQuNGC0LDQu9C40Lkg0KTQsNC0?= =?UTF-8?B?0LXQtdCy?= writes:
Have:
     void process( ref MouseKeyEvent event )
     {
        ...
     }

     void process( ref MouseMoveEvent event )
     {
        ...
     }

Want:
     _processMouseKey  = &process; // <-- not works
     _processMouseMove = &process; // <-- not works

What is correct way to get address of function with specific 
argument ?
Mar 11
next sibling parent reply Paul Backus <snarwin gmail.com> writes:
On Thursday, 11 March 2021 at 12:26:07 UTC, Виталий Фадеев wrote:
 Have:
     void process( ref MouseKeyEvent event )
     {
        ...
     }

     void process( ref MouseMoveEvent event )
     {
        ...
     }

 Want:
     _processMouseKey  = &process; // <-- not works
     _processMouseMove = &process; // <-- not works

 What is correct way to get address of function with specific 
 argument ?
You can use __traits(getOverloads, process) plus some metaprogramming to get the address of a specific overload. But IMO the easiest way is to use lambdas: __processMouseKey = (ref MouseKeyEvent event) { process(event); }; __processMouseMove = (ref MouseMoveEvent event) { process(event); };
Mar 11
parent reply =?UTF-8?B?0JLQuNGC0LDQu9C40Lkg0KTQsNC0?= =?UTF-8?B?0LXQtdCy?= writes:
On Thursday, 11 March 2021 at 12:48:13 UTC, Paul Backus wrote:
 On Thursday, 11 March 2021 at 12:26:07 UTC, Виталий Фадеев 
 wrote:
 Have:
     void process( ref MouseKeyEvent event )
     {
        ...
     }

     void process( ref MouseMoveEvent event )
     {
        ...
     }

 Want:
     _processMouseKey  = &process; // <-- not works
     _processMouseMove = &process; // <-- not works

 What is correct way to get address of function with specific 
 argument ?
You can use __traits(getOverloads, process) plus some metaprogramming to get the address of a specific overload. But IMO the easiest way is to use lambdas: __processMouseKey = (ref MouseKeyEvent event) { process(event); }; __processMouseMove = (ref MouseMoveEvent event) { process(event); };
This will generate lambda: __processMouseKey = (ref MouseKeyEvent event) { process(event); }; two calls: call labnda; call process; What right way to call function directly with selecting one of two ?
Mar 11
next sibling parent reply Paul Backus <snarwin gmail.com> writes:
On Thursday, 11 March 2021 at 12:56:34 UTC, Виталий Фадеев wrote:
 This will generate lambda:
   __processMouseKey = (ref MouseKeyEvent event) { 
 process(event); };

 two calls:
   call labnda;
     call process;

 What right way to call function directly with selecting one of 
 two ?
Something like this: template Overloads(alias symbol) { static if (__traits(compiles, __traits(parent, symbol))) alias Overloads = __traits(getOverloads, __traits(parent, symbol), __traits(identifier, symbol) ); else alias Overloads = symbol; } auto getOverloadFor(alias fun, T)() { foreach (overload; Overloads!fun) static if (__traits(compiles, (T arg) { overload(arg); })) return &overload; } Usage: __processMouseKey = getOverloadFor!(process, MouseKeyEvent);
Mar 11
parent =?UTF-8?B?0JLQuNGC0LDQu9C40Lkg0KTQsNC0?= =?UTF-8?B?0LXQtdCy?= writes:
On Thursday, 11 March 2021 at 13:14:56 UTC, Paul Backus wrote:
 On Thursday, 11 March 2021 at 12:56:34 UTC, Виталий Фадеев 
 wrote:
 [...]
Something like this: template Overloads(alias symbol) { static if (__traits(compiles, __traits(parent, symbol))) alias Overloads = __traits(getOverloads, __traits(parent, symbol), __traits(identifier, symbol) ); else alias Overloads = symbol; } auto getOverloadFor(alias fun, T)() { foreach (overload; Overloads!fun) static if (__traits(compiles, (T arg) { overload(arg); })) return &overload; } Usage: __processMouseKey = getOverloadFor!(process, MouseKeyEvent);
Thanks a lot, bro!
Mar 11
prev sibling parent Dennis <dkorpel gmail.com> writes:
On Thursday, 11 March 2021 at 12:56:34 UTC, Виталий Фадеев wrote:
 What right way to call function directly with selecting one of 
 two ?
If they are not nested functions, you can also do: ``` // Separate names void processKey (ref MouseKeyEvent event) {...} void processMove(ref MouseMoveEvent event) {...} // Still create overload set alias process = processKey; alias process = processMove; _processMouseKey = &processKey; _processMouseMove = &processMove; ```
Mar 11
prev sibling parent reply Adam D. Ruppe <destructionator gmail.com> writes:
On Thursday, 11 March 2021 at 12:26:07 UTC, Виталий Фадеев wrote:
     _processMouseKey  = &process; // <-- not works
     _processMouseMove = &process; // <-- not works
This *should* actually work. What type are those variables? struct MouseKeyEvent {} struct MouseMoveEvent{} void process( ref MouseKeyEvent event ) { } void process( ref MouseMoveEvent event ) { } void main() { // this works because the type is given on the left // so the compiler knows which overload works void function(ref MouseMoveEvent) processMouseMove = &process; }
Mar 11
parent =?UTF-8?B?0JLQuNGC0LDQu9C40Lkg0KTQsNC0?= =?UTF-8?B?0LXQtdCy?= writes:
On Thursday, 11 March 2021 at 14:23:39 UTC, Adam D. Ruppe wrote:
 On Thursday, 11 March 2021 at 12:26:07 UTC, Виталий Фадеев 
 wrote:
     _processMouseKey  = &process; // <-- not works
     _processMouseMove = &process; // <-- not works
This *should* actually work. What type are those variables? struct MouseKeyEvent {} struct MouseMoveEvent{} void process( ref MouseKeyEvent event ) { } void process( ref MouseMoveEvent event ) { } void main() { // this works because the type is given on the left // so the compiler knows which overload works void function(ref MouseMoveEvent) processMouseMove = &process; }
I was stupid. It is really simple! Thank a lot, bro!
Mar 11