Re: [Vala] Accessing properties of a Map.Entry from a read-only Gee map causes compiler warning

[Al Thomas <astavale yahoo co uk>]

> From: Nicolas Laplante <nicolas laplante gmail com>

> Sent: Thursday, 19 November 2015, 19:33
> Subject: [Vala] Accessing properties of a Map.Entry from a read-only Gee map causes compiler warning
>
> foreach (Map.Entry<GB.Model.Date, Gee.List<Transaction>> entry in
> transactions_by_date.entries) {
>     // ...
> }
>
> Within this loop, whenver I access entry.key or entry.value, I get the
> following compiler warning:
>
> src/ui/tree_store_transaction.vala:284:14: warning: assignment discards
> ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers]
>                          debug ("transaction group: %s (%d
> transaction(s))", entry.key.to_string (), entry.value.size);
>
> I get this warning for each line accessing properties of the "entry"
> variable. Is this normal?


It is "normal" in the sense that I also get these warnings from the
C compiler and the generated binary still works fine.

Ideally the generated C code from the Vala compiler would produce
code that avoided these warnings, but that means digging deep.

If you are finding the C compiler warnings distracting from 

Vala compiler warnings then you can add the option:
-X -w 
to the valac command. This passes a message to the C compiler to 

not show the warnings.

See also:
http://stackoverflow.com/questions/19468179/understanding-vala-compilation-warnings

Al