There is a proposal to add several user-defined literals to the standard
library that looks like it will probably go through:
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3468.pdf
The proposed string literals
std::string hw = "Hello, world!"s;
will not parse as a literal in gcc.
This patch fixes this by modifying the lexing of "string"XYZ
user-defined literals as *two* tokens if the suffix starts with a letter
*unless the letter is a lower-case 's'*. i.e. don't parse as a
user-defined literal but as a sequence of string and macro *unless
starts with lower case 's'*.
The original code parsed all string literals with suffix beginning with
any letter as a sequence of string and macro (two tokens, not one).
Thanks,
Index: libcpp/lex.c
===================================================================
--- libcpp/lex.c (revision 194178)
+++ libcpp/lex.c (working copy)
@@ -1562,8 +1562,10 @@
from inttypes.h, we generate a warning and treat the ud-suffix as a
separate preprocessing token. This approach is under discussion by
the standards committee, and has been adopted as a conforming
- extension by other front ends such as clang. */
- if (ISALPHA (*cur))
+ extension by other front ends such as clang.
+ A special exception is made for the suffix 's' which will be
+ standardized as a user-defined literal suffix for strings. */
+ if (ISALPHA (*cur) && *cur != 's')
{
/* Raise a warning, but do not consume subsequent tokens. */
if (CPP_OPTION (pfile, warn_literal_suffix))
@@ -1573,7 +1575,7 @@
"a space between literal and identifier");
}
/* Grab user defined literal suffix. */
- else if (*cur == '_')
+ else if (ISIDST (*cur))
{
type = cpp_userdef_string_add_type (type);
++cur;
@@ -1693,8 +1695,10 @@
from inttypes.h, we generate a warning and treat the ud-suffix as a
separate preprocessing token. This approach is under discussion by
the standards committee, and has been adopted as a conforming
- extension by other front ends such as clang. */
- if (ISALPHA (*cur))
+ extension by other front ends such as clang.
+ A special exception is made for the suffix 's' which will be
+ standardized as a user-defined literal suffix for strings. */
+ if (ISALPHA (*cur) && *cur != 's')
{
/* Raise a warning, but do not consume subsequent tokens. */
if (CPP_OPTION (pfile, warn_literal_suffix))
@@ -1704,7 +1708,7 @@
"a space between literal and identifier");
}
/* Grab user defined literal suffix. */
- else if (*cur == '_')
+ else if (ISIDST (*cur))
{
type = cpp_userdef_char_add_type (type);
type = cpp_userdef_string_add_type (type);
Index: gcc/testsuite/g++.dg/cpp0x/udlit-string-literal.C
===================================================================
--- gcc/testsuite/g++.dg/cpp0x/udlit-string-literal.C (revision 0)
+++ gcc/testsuite/g++.dg/cpp0x/udlit-string-literal.C (revision 0)
@@ -0,0 +1,12 @@
+// { dg-options "-std=c++11" }
+// PR c++/55582
+
+#include "udlit-string-literal.h"
+
+using namespace my_string_literals;
+
+decltype("Hello, World!"s) s;
+decltype(u8"Hello, World!"s) s8;
+decltype(L"Hello, World!"s) ws;
+decltype(u"Hello, World!"s) s16;
+decltype(U"Hello, World!"s) s32;
Index: gcc/testsuite/g++.dg/cpp0x/udlit-string-literal.h
===================================================================
--- gcc/testsuite/g++.dg/cpp0x/udlit-string-literal.h (revision 0)
+++ gcc/testsuite/g++.dg/cpp0x/udlit-string-literal.h (revision 0)
@@ -0,0 +1,22 @@
+#pragma GCC system_header
+
+#include <string>
+
+inline namespace my_string_literals
+{
+ std::string
+ operator"" s(const char* str, std::size_t len)
+ { return std::string{str, len}; }
+
+ std::wstring
+ operator"" s(const wchar_t* str, std::size_t len)
+ { return std::wstring{str, len}; }
+
+ std::u16string
+ operator"" s(const char16_t* str, std::size_t len)
+ { return std::u16string{str, len}; }
+
+ std::u32string
+ operator"" s(const char32_t* str, std::size_t len)
+ { return std::u32string{str, len}; }
+}
gcc/libcpp/
2012-12-05 Ed Smith-Rowland <3dw...@verizon.net>
PR c++/55582
* lex.c (lex_raw_string): Allow string literal with suffix starting with
lower-case 's' as a user-defined literal.
(lex_string): Ditto.
gcc/testsuite/
2012-12-05 Ed Smith-Rowland <3dw...@verizon.net>
PR c++/55582
* g++.dg/cpp0x/udlit-string-literal.h: New.
* g++.dg/cpp0x/udlit-string-literal.C: New.
