Re: [lmi] Converting std::string to wxString

[Greg Chicares]

On 2017-02-06 15:17, Vadim Zeitlin wrote:
> On Mon,  6 Feb 2017 04:10:56 +0000 (UTC) Greg Chicares <address@hidden> wrote:
[...]
> GC> +        return wxString(parser_diagnostics.c_str());

That replaced this:
-    wxString msg = sequence.formatted_diagnostics(true).c_str();

and this is VS's original from 2011:
+    return sequence.formatted_diagnostics().c_str();

so I was in no rush to make a speculative change that might be incorrect.
But now on your assurance I have changed it, in a commit that I have not
yet pushed.

>  This is not really related to the changes of this patch series, but while
> reading them I noticed this line and just wanted to say that an explicit
> call to "c_str()" is not needed with any relatively recent version of
> wxWidgets (i.e. since many years) as wxString has a ctor from std::string
> (unless it was explicitly disabled by setting wxUSE_STD_STRING, which is 1
> by default, to 0).

Perhaps some people would wish to override that, but I am not one of them.

> Moreover, this ctor is implicit, so you don't even need

Implicit? It's been years since I looked at the wx sources, but I thought
it was a typedef. Wait...no, it can't be, because wxString has all those
extra functions--I must have been thinking of the container classes.

Oh...and wxString handles UTF-8. Maybe in C++37.

> to write "wxString(...)" neither, so the last added line above could be
> rewritten either as
> 
>       return wxString(parser_diagnostics);
> 
> or even as just
> 
>       return parser_diagnostics;

Yes, that's best.

>  I'm not sure if the latter is not too magic and I'd understand if you
> preferred to keep "wxString(...)" for clarity, but I'd definitely remove
> ".c_str()" which is just superfluous.
> 
>  Finally, for completeness, notice that the situation in the other
> direction is, unfortunately, not symmetric as we can't add a ctor from
> wxString to std::string class, so you still have to explicitly call
> wxString::ToStdString() to convert a wxString to std::string.

We've been having this discussion for ages, and I never can remember
what the rules are. But let me ask this: if I just do whatever seems
simplest to me, can I trust the compiler to give a warning whenever
I've oversimplified? "Code for simplicity, but don't commit anything
that doesn't compile" is a rule I can memorize.