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Re: user-defined literals and macros

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Am 30.10.2011 19:09, schrieb cryptooctoploid@gmail.com:
> Consider:
>    % cat liter.cpp
> #define BAR "foo"
> int main()
> {
>     char *foobar("foo/"BAR);
> }
>
>    % g++ liter.cpp -std=gnu++0x
> liter.cpp: In function ‘int main()’:
> liter.cpp:4:16: error: unable to find user-defined string literal operator ‘operator"" BAR’
>
> Is this the expected behavior?

Yes, this is a known backward-compatibility break of C++11, it is listed
in annex C.2.1, 2.5:

<quote>
Change: User-defined literal string support
Rationale: Required for new features.
Effect on original feature: Valid C++ 2003 code may fail to compile or
produce different results in this International Standard, as the
following example illustrates.

#define _x "there"
"hello"_x // #1

Previously, #1 would have consisted of two separate preprocessing tokens
and the macro _x would have been expanded. In this International
Standard, #1 consists of a single preprocessing tokens, so the macro
is not expanded.
</quote>

HTH & Greetings from Bremen,

Daniel Krügler


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user-defined literals and macros cryptooctoploid@gmail.com - 2011-10-30 11:09 -0700
  Re: user-defined literals and macros Johannes Schaub <schaub.johannes@googlemail.com> - 2011-10-31 11:10 -0700
  Re: user-defined literals and macros David Krauss <potswa@gmail.com> - 2011-10-31 11:11 -0700
  Re: user-defined literals and macros Ed Smith-Rowland <3dw4rd@verizon.net> - 2011-10-31 11:11 -0700
    Re: user-defined literals and macros Ed Smith-Rowland<3dw4rd@verizon.net> - 2011-11-01 11:14 -0700
  Re: user-defined literals and macros Daniel Krügler <daniel.kruegler@googlemail.com> - 2011-10-31 11:12 -0700

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