Alternatives to exceptions for error handling

[Paul Backus]

On Monday, 23 November 2020 at 02:14:33 UTC, Vladimir Panteleev 
wrote:
> Another approach that I'm not sure we've explored fully is to 
> outright deprecate silently discarding all function return 
> values. Functions which return a value that is only sometimes 
> useful seem like a relatively rare oddity.

The main advantage of @nodiscard compared to this approach is 
that it can interact with the type system. For example, if I 
declare a struct like the following:

@nodiscard Result(T, E)
{
     SumType!(T, E) payload;
     // ...
}

...then every expression that evaluates to a Result (not just 
function calls!) automatically becomes non-discardable.