Re: enums and switch vs function calls

On 06/04/2025 16:47, Scott Lurndal wrote:

Tim Rentsch <tr.17687@z991.linuxsc.com> writes:

scott@slp53.sl.home (Scott Lurndal) writes:
>

ram@zedat.fu-berlin.de (Stefan Ram) writes:
>

Richard Harnden <richard.nospam@gmail.invalid> wrote or quoted:
>

int hex = colour_to_hex(10);
... then the compiler doesn't complain that 10 is not in the enum.
Why?  Surely the compiler can tell.

>
  I get
>
|
|error: enum conversion when passing argument 1 of 'colour_to_hex' is
invalid in C++ [-Wc++-compat]
|      |int hex = colour_to_hex(10);
|      |                        ^~
|note: expected 'enum colour' but argument is of type 'int'
|      | int colour_to_hex(enum colour colour)
|      |     ^~~~~~~~~~~~~
|
>
  with
>
gcc -Wc++-compat

>
That example exemplifies the seriously screwed up error reporting in the
gnu compiler collection.
>
One line of informative error message followed by 5 lines of useless
cruft to wade through.  And no way to turn it off completely.

>
That's true, but it can be reduced to only two lines total (so only one
line more than needed), by using -fno-diagnostics-show-caret.

 Yes, I use that.  I still find that the "note:" lines clutter the
output and provide zero benefit.

Sometimes you can immediately spot the cause of an error - you've made a typo and all you need is a vague indication that there is a mistake somewhere in that area.  Other times the cause can be quite subtle, especially in C++, and the extra information can be of great help. Unfortunately, it's impossible for the compiler to tell which situation you are in.
I'm sure you are aware of the "-fdiagnostic" options for fine-tuning the appearance of error messages - I have no idea if they can be used to trim them down to something that suits you.