Hi,

Someone reminded me of my erroneous logging function:

LogWarn("Invalid Value {}", GetValue());

The function is defined like this:

template<typename... Ts>

void LogWarn(std::string_view fmt, Ts&&... args)

{

#if defined(LOG_WARN)

    // log...

#endif

}

Problem is that the function call to GetValue() is always evaluated, even if the result is not used.

It is undesireable for me to check the macro LOG_WARN in user-code every time I have to log,

and because this is a modularized approach I would like to avoid needing to include a logging header.

In my ideal world, I could define my logging function like this:

[[ConditionalDiscard = IsShipping()]]

template<typename... Ts>

void LogWarn(std::string_view fmt, Ts&&... args) { /* ... */ }

I assume the function IsShipping() to be constexpr.

And the effect would be a function call completely stripped 

Only reason I didn't post on StackOverflow is because I feel we are getting inside proposal territory.

Looking forward to your inputs!