• Vitalii (12/12) Jul 15 2020 Hello everyone!
• WebFreak001 (39/53) Jul 15 2020 that wiki entry is from 2012. __FUNCTION__, __PRETTY_FUNCTION__
• Vitalii (1/1) Jul 15 2020 Many thanks!
• WebFreak001 (3/4) Jul 16 2020 I have now deprecated the old wiki page and linked to a new one

Vitalii <yvitaliy1980 yandex.ru> writes:

Hello everyone!

I try to compile this recipe with dmd (2.089.0), ldc2 (1.18.0):
https://wiki.dlang.org/Using_string_mixins_for_logging
but get the same error:

mixin_log.d(64): Error: basic type expected, not __FUNCTION__
mixin_log.d(64): Error: declaration expected, not __FUNCTION__

in that part of code:

mixin template set_func_name(string fn)
{
     enum __FUNCTION__ = fn;
}

There is no doubt that this recipe once worked. How to fix it now?

WebFreak001 <d.forum webfreak.org> writes:

On Wednesday, 15 July 2020 at 07:07:55 UTC, Vitalii wrote:
 Hello everyone!

 I try to compile this recipe with dmd (2.089.0), ldc2 (1.18.0):
 https://wiki.dlang.org/Using_string_mixins_for_logging
 but get the same error:

 mixin_log.d(64): Error: basic type expected, not __FUNCTION__
 mixin_log.d(64): Error: declaration expected, not __FUNCTION__

 in that part of code:

 mixin template set_func_name(string fn)
 {
     enum __FUNCTION__ = fn;
 }

 There is no doubt that this recipe once worked. How to fix it 
 now?

that wiki entry is from 2012. __FUNCTION__, __PRETTY_FUNCTION__ 
and __MODULE__ were introduced in 2013, making that old 
__FUNCTION__ definition code obsolete.

In fact all of the code on that page can now be more easily 
written as:


enum LogLevel { INFO, WARN, ERROR }

template log(LogLevel level)
{
     void log(Args...)(Args args, string fn = __FUNCTION__, string 
file = __FILE__, size_t line = __LINE__)
     {
         writeln(Clock.currTime(), " [", level, "] ", file, '(', 
line, "): ", fn, ": ", args);
     }
}

alias info = log!(LogLevel.INFO);
alias warn = log!(LogLevel.WARN);
alias error = log!(LogLevel.ERROR);


no longer requiring any mixins or boilerplate code in your 
calling functions.

---

void main(string[] args)
{
     info("hello", "world");
     warn("i am ", "number ", 1);
     error(true);
     log!(LogLevel.INFO)("manual call");
}




2020-Jul-15 08:12:00.5900346 [INFO] onlineapp.d(21): 
onlineapp.main: helloworld
2020-Jul-15 08:12:00.5901559 [WARN] onlineapp.d(22): 
onlineapp.main: i am number 1
2020-Jul-15 08:12:00.5901745 [ERROR] onlineapp.d(23): 
onlineapp.main: true

---

This uses default values after variadic parameters which is 
allowed since 2.079.0 and also uses a nested template to allow 
for the aliases with default LogLevel.

Vitalii <yvitaliy1980 yandex.ru> writes:

Many thanks!

WebFreak001 <d.forum webfreak.org> writes:

On Wednesday, 15 July 2020 at 07:36:49 UTC, Vitalii wrote:
 Many thanks!

I have now deprecated the old wiki page and linked to a new one 
with more examples: https://wiki.dlang.org/Logging_mechanisms