From 8aa60b51a9e48b33ba6f0cb27132c6a415de2358 Mon Sep 17 00:00:00 2001 From: Luboš Luňák Date: Thu, 29 Mar 2012 11:03:47 +0200 Subject: (const) char[] (i.e. size unknown) cannot be used with O(U)String msvc can't handle the necessary template overload (and maybe it's right, I'm not sure) --- sal/inc/rtl/stringutils.hxx | 9 +++++++++ sal/qa/rtl/strings/test_ostring_stringliterals.cxx | 19 ++++++++++++++++--- 2 files changed, 25 insertions(+), 3 deletions(-) (limited to 'sal') diff --git a/sal/inc/rtl/stringutils.hxx b/sal/inc/rtl/stringutils.hxx index 19c1bf460fb4..3ed36a758aaa 100644 --- a/sal/inc/rtl/stringutils.hxx +++ b/sal/inc/rtl/stringutils.hxx @@ -65,6 +65,12 @@ There are 2 cases: cast to const char*. Additionally (non-const) char[N] needs to be handled, but with the reference being const, it would also match const char[N], so another overload with a reference to non-const and NonConstCharArrayDetector are used to ensure the function is called only with (non-const) char[N]. +Additionally, char[] and const char[] (i.e. size unknown) are rather tricky. Their usage with 'T&' would +mean it would be 'char(&)[]', which seems to be invalid. But gcc and clang somehow manage when it is +a template. while msvc complains about no conversion from char[] to char[1]. And the reference cannot +be avoided, because 'const char[]' as argument type would match also 'const char[N]' +So char[] and const char[] should always be used with their contents specified (which automatically +turns them into char[N] or const char[N]), or char* and const char* should be used. */ struct Dummy {}; template< typename T1, typename T2 > @@ -91,6 +97,8 @@ struct NonConstCharArrayDetector< char[ N ], T > { typedef T Type; }; +#ifdef RTL_STRING_UNITTEST +// never use, until all compilers handle this template< typename T > struct NonConstCharArrayDetector< char[], T > { @@ -101,6 +109,7 @@ struct NonConstCharArrayDetector< const char[], T > { typedef T Type; }; +#endif template< typename T1, typename T2 > struct ConstCharArrayDetector diff --git a/sal/qa/rtl/strings/test_ostring_stringliterals.cxx b/sal/qa/rtl/strings/test_ostring_stringliterals.cxx index 0d5036aa2f11..d7e3cf5be7c4 100644 --- a/sal/qa/rtl/strings/test_ostring_stringliterals.cxx +++ b/sal/qa/rtl/strings/test_ostring_stringliterals.cxx @@ -66,6 +66,9 @@ private: void testcall( const char str[] ); + static const char bad5[]; + static char bad6[]; + CPPUNIT_TEST_SUITE(StringLiterals); CPPUNIT_TEST(checkCtors); CPPUNIT_TEST(checkUsage); @@ -100,13 +103,20 @@ void test::ostring::StringLiterals::checkCtors() const char* bad4[] = { "test1" }; CPPUNIT_ASSERT( !CONST_CTOR_USED( bad4[ 0 ] )); testcall( good1 ); +#ifndef _MSC_VER + // this is actually not supposed to work (see discussion in stringutils.hxx), + // but gcc and clang somehow manage, so keep it used, just in case some other problem + // shows up somewhen in the future + CPPUNIT_ASSERT( !CONST_CTOR_USED( bad5 )); // size is not known here + CPPUNIT_ASSERT( !CONST_CTOR_USED( bad6 )); +#endif // This one is technically broken, since the first element is 6 characters test\0\0, // but there does not appear a way to detect this by compile time (runtime will complain). // RTL_CONSTASCII_USTRINGPARAM() has the same flaw. - const char bad5[][ 6 ] = { "test", "test2" }; - CPPUNIT_ASSERT( CONST_CTOR_USED( bad5[ 0 ] )); - CPPUNIT_ASSERT( CONST_CTOR_USED( bad5[ 1 ] )); + const char bad7[][ 6 ] = { "test", "test2" }; + CPPUNIT_ASSERT( CONST_CTOR_USED( bad7[ 0 ] )); + CPPUNIT_ASSERT( CONST_CTOR_USED( bad7[ 1 ] )); // Check that contents are correct and equal to the case when const char* ctor is used. CPPUNIT_ASSERT( rtl::OString( (const char*)"" ) == rtl::OString( "" )); @@ -128,6 +138,9 @@ void test::ostring::StringLiterals::checkCtors() #endif } +const char test::ostring::StringLiterals::bad5[] = "test"; +char test::ostring::StringLiterals::bad6[] = "test"; + void test::ostring::StringLiterals::testcall( const char str[] ) { #ifndef _MSC_VER -- cgit