Logging function name, line, file...

[Bill Baxter]

Bruno Medeiros wrote:
> Jaro wrote:
>> Is it possible to log file name, line, and function name in D like it 
>> was in C++ when we could hide __FILE__, __LINE__, __FUNCTION__ in a 
>> new logging macro? That way this information was printed in log file, 
>> and was extremely useful.
> 
> You can use mixins to achieve that. Not as direct as C++ macros, but 
> it's the cleanest you get:
> 
> -----  -----
> import std.stdio;
> import std.string;
> 
> 
> void log(string msg) {
>     writefln("LOG: " ~ msg);
> }
> 
> string logm(string msg) {
>     return `log(__FILE__ ~":"~ toString(__LINE__) ~ " `~msg~`");`;
> }
> 
> void main()
> {
>      mixin(logm("entering main!"));
>     auto numbers = [4, 8, 15, 16, 23, 42];
>     mixin(logm("exiting main!"));
> }
> 
> -----  -----
> Outputs:
> 
> LOG: src\test.d:15 entering main!
> LOG: src\test.d:17 exiting main!
> 
> Is this what you intended?
> 


Maybe this should go in a FAQ before it gets asked & answered another 5 
times?

--bb