1 //===----------------------------------------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 // <ostream> 11 12 // template <class charT, class traits = char_traits<charT> > 13 // class basic_ostream; 14 15 // operator<<(const void* val); 16 17 #include <ostream> 18 #include <cassert> 19 20 template <class CharT> 21 class testbuf 22 : public std::basic_streambuf<CharT> 23 { 24 typedef std::basic_streambuf<CharT> base; 25 std::basic_string<CharT> str_; 26 public: testbuf()27 testbuf() 28 { 29 } 30 str() const31 std::basic_string<CharT> str() const 32 {return std::basic_string<CharT>(base::pbase(), base::pptr());} 33 34 protected: 35 36 virtual typename base::int_type overflow(typename base::int_type __c=base::traits_type::eof ())37 overflow(typename base::int_type __c = base::traits_type::eof()) 38 { 39 if (__c != base::traits_type::eof()) 40 { 41 int n = str_.size(); 42 str_.push_back(__c); 43 str_.resize(str_.capacity()); 44 base::setp(const_cast<CharT*>(str_.data()), 45 const_cast<CharT*>(str_.data() + str_.size())); 46 base::pbump(n+1); 47 } 48 return __c; 49 } 50 }; 51 main()52int main() 53 { 54 { 55 std::ostream os((std::streambuf*)0); 56 const void* n = 0; 57 os << n; 58 assert(os.bad()); 59 assert(os.fail()); 60 } 61 { 62 testbuf<char> sb; 63 std::ostream os(&sb); 64 const void* n = 0; 65 os << n; 66 assert(os.good()); 67 // %p is implementation defined. 68 // On some platforms (Windows), it's a hex number without 69 // any leading 0x like prefix. 70 // In that format, we assume a null pointer will yield 2 '0' hex digits 71 // for each 8 bits of address space. 72 assert(sb.str() == "0x0" || sb.str() == "(nil)" || 73 sb.str() == std::string(sizeof(void*)*2,'0')); 74 } 75 { 76 testbuf<char> sb; 77 std::ostream os(&sb); 78 const void* n = &sb; 79 os << n; 80 assert(os.good()); 81 } 82 } 83