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 // template<class traits> 16 // basic_ostream<char,traits>& operator<<(basic_ostream<char,traits>& out, const char* s); 17 18 #include <ostream> 19 #include <cassert> 20 21 template <class CharT> 22 class testbuf 23 : public std::basic_streambuf<CharT> 24 { 25 typedef std::basic_streambuf<CharT> base; 26 std::basic_string<CharT> str_; 27 public: 28 testbuf() 29 { 30 } 31 32 std::basic_string<CharT> str() const 33 {return std::basic_string<CharT>(base::pbase(), base::pptr());} 34 35 protected: 36 37 virtual typename base::int_type 38 overflow(typename base::int_type ch = base::traits_type::eof()) 39 { 40 if (ch != base::traits_type::eof()) 41 { 42 int n = static_cast<int>(str_.size()); 43 str_.push_back(static_cast<CharT>(ch)); 44 str_.resize(str_.capacity()); 45 base::setp(const_cast<CharT*>(str_.data()), 46 const_cast<CharT*>(str_.data() + str_.size())); 47 base::pbump(n+1); 48 } 49 return ch; 50 } 51 }; 52 53 int main() 54 { 55 { 56 std::ostream os((std::streambuf*)0); 57 const char* c = "123"; 58 os << c; 59 assert(os.bad()); 60 assert(os.fail()); 61 } 62 { 63 testbuf<char> sb; 64 std::ostream os(&sb); 65 const char* c = "123"; 66 os << c; 67 assert(sb.str() == "123"); 68 } 69 { 70 testbuf<char> sb; 71 std::ostream os(&sb); 72 os.width(5); 73 const char* c = "123"; 74 os << c; 75 assert(sb.str() == " 123"); 76 assert(os.width() == 0); 77 } 78 { 79 testbuf<char> sb; 80 std::ostream os(&sb); 81 os.width(5); 82 left(os); 83 const char* c = "123"; 84 os << c; 85 assert(sb.str() == "123 "); 86 assert(os.width() == 0); 87 } 88 } 89
