124 lines · cpp
1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9// <istream>10 11// basic_istream<charT,traits>& read(char_type* s, streamsize n);12 13#include <istream>14#include <cassert>15#include <streambuf>16 17#include "test_macros.h"18 19template <class CharT>20struct testbuf21 : public std::basic_streambuf<CharT>22{23 typedef std::basic_string<CharT> string_type;24 typedef std::basic_streambuf<CharT> base;25private:26 string_type str_;27public:28 29 testbuf() {}30 testbuf(const string_type& str)31 : str_(str)32 {33 base::setg(const_cast<CharT*>(str_.data()),34 const_cast<CharT*>(str_.data()),35 const_cast<CharT*>(str_.data()) + str_.size());36 }37 38 CharT* eback() const {return base::eback();}39 CharT* gptr() const {return base::gptr();}40 CharT* egptr() const {return base::egptr();}41};42 43int main(int, char**)44{45 {46 testbuf<char> sb(" 123456789");47 std::istream is(&sb);48 char s[5];49 is.read(s, 5);50 assert(!is.eof());51 assert(!is.fail());52 assert(std::string(s, 5) == " 1234");53 assert(is.gcount() == 5);54 is.read(s, 5);55 assert(!is.eof());56 assert(!is.fail());57 assert(std::string(s, 5) == "56789");58 assert(is.gcount() == 5);59 is.read(s, 5);60 assert( is.eof());61 assert( is.fail());62 assert(is.gcount() == 0);63 }64#ifndef TEST_HAS_NO_WIDE_CHARACTERS65 {66 testbuf<wchar_t> sb(L" 123456789");67 std::wistream is(&sb);68 wchar_t s[5];69 is.read(s, 5);70 assert(!is.eof());71 assert(!is.fail());72 assert(std::wstring(s, 5) == L" 1234");73 assert(is.gcount() == 5);74 is.read(s, 5);75 assert(!is.eof());76 assert(!is.fail());77 assert(std::wstring(s, 5) == L"56789");78 assert(is.gcount() == 5);79 is.read(s, 5);80 assert( is.eof());81 assert( is.fail());82 assert(is.gcount() == 0);83 }84#endif85#ifndef TEST_HAS_NO_EXCEPTIONS86 {87 testbuf<char> sb;88 std::basic_istream<char> is(&sb);89 is.exceptions(std::ios_base::eofbit);90 char s[10];91 bool threw = false;92 try {93 is.read(s, 5);94 } catch (std::ios_base::failure&) {95 threw = true;96 }97 assert(threw);98 assert(!is.bad());99 assert( is.eof());100 assert( is.fail());101 }102#ifndef TEST_HAS_NO_WIDE_CHARACTERS103 {104 testbuf<wchar_t> sb;105 std::basic_istream<wchar_t> is(&sb);106 is.exceptions(std::ios_base::eofbit);107 wchar_t s[10];108 bool threw = false;109 try {110 is.read(s, 5);111 } catch (std::ios_base::failure&) {112 threw = true;113 }114 assert(threw);115 assert(!is.bad());116 assert( is.eof());117 assert( is.fail());118 }119#endif120#endif // TEST_HAS_NO_EXCEPTIONS121 122 return 0;123}124