The following code:

{$MODE DELPHI}
program CharOverload;
uses
   SysUtils;
procedure Foo(const aArg: UnicodeString); overload;
begin
   WriteLn('WideString: ', aArg);
end;
procedure Foo(c: WideChar); overload;
begin
   WriteLn('Char: ', c);
end;
begin
   Foo('abc');
end.

Fails with current trunk fpc with the following messages

[odysseus:fpc-trunk$] compiler/ppc386 ~/Desktop/test/CharOverload.pp Free Pascal Compiler version 3.1.1 [2018/06/18] for i386 Copyright (c) 1993-2018 by Florian Klaempfl and others Target OS: Darwin for i386
Compiling /Users/djenkins/Desktop/test/CharOverload.pp CharOverload.pp(19,3) Error: Can't determine which overloaded function to call
CharOverload.pp(19,12) Error: Illegal type conversion: "Constant String" to "WideChar"
CharOverload.pp(20,4) Fatal: There were 2 errors compiling module, stopping Fatal: Compilation aborted

It fails with same messages with {$MODE OBJFPC}.  Is this known. I can enter a Mantis if desired.

Thanks

David Jenkins

Hey David,
The compiler says "Can't determine which overloaded function to call" because both are strings.

Marcos Douglas

This is something that has just recently stopped working for us(with update to current trunk). We previously were using trunk rev 36812 with no problems.

Placing a second call

foo('a')

calls the expected WideChar version.

David

David Jenkins wrote

This is something that has just recently stopped working for us(with update to current trunk).  We previously were using trunk rev 36812 with no problems.

Please submit a bug report to mantis.

Done.  Mantis 33875.

Sorry, but how the compiler will know the correct string type of 'a'?

Technically it's a regression because it worked fine before and it breaks now.  However, I do agree... how should a string literal be interpreted? Technically either a WideString or UnicodeString is correct, so the compiler cannot decide between them or even know what the best fit is.

Gareth

On Tue 19/06/18 00:38 , "Marcos Douglas B. Santos" sent:

Sorry, but how the compiler will know the correct string type of 'a'?

It's an overload between UnicodeString and WideCHAR, not WideString, so there is a definitive difference.

Regards,
Sven

Oh whoops. My mistake.

On Tue 19/06/18 06:18 , Sven Barth via
fpc-devel
sent:

Am 19.06.2018 um 02:47 schrieb J. Gareth

Moreton:

Technically it's a regression because it

worked fine before and it

breaks now.  However, I do agree... how

should a string literal be

interpreted? Technically either a

WideString or UnicodeString is correct,

so the compiler cannot decide between

them or even know what the best fit

is. It's an overload between

UnicodeString and WideCHAR, not
WideString, so