 256813f4e7
			
		
	
	256813f4e7
	
	
	
		
			
			git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@111758 91177308-0d34-0410-b5e6-96231b3b80d8
		
			
				
	
	
		
			57 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			57 lines
		
	
	
		
			1.6 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| //===----------------------------------------------------------------------===//
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| //
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| //                     The LLVM Compiler Infrastructure
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| //
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| // This file is distributed under the University of Illinois Open Source
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| // License. See LICENSE.TXT for details.
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| //
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| //===----------------------------------------------------------------------===//
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| 
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| // <fstream>
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| 
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| // int_type pbackfail(int_type c = traits::eof());
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| 
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| // This test is not entirely portable
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| 
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| #include <fstream>
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| #include <cassert>
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| 
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| template <class CharT>
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| struct test_buf
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|     : public std::basic_filebuf<CharT>
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| {
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|     typedef std::basic_filebuf<CharT>  base;
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|     typedef typename base::char_type   char_type;
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|     typedef typename base::int_type    int_type;
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|     typedef typename base::traits_type traits_type;
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| 
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|     char_type* eback() const {return base::eback();}
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|     char_type* gptr()  const {return base::gptr();}
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|     char_type* egptr() const {return base::egptr();}
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|     void gbump(int n) {base::gbump(n);}
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| 
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|     virtual int_type pbackfail(int_type c = traits_type::eof()) {return base::pbackfail(c);}
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| };
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| 
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| int main()
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| {
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|     {
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|         test_buf<char> f;
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|         assert(f.open("underflow.dat", std::ios_base::in) != 0);
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|         assert(f.is_open());
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|         assert(f.sbumpc() == '1');
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|         assert(f.sgetc() == '2');
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|         assert(f.pbackfail('a') == -1);
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|     }
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|     {
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|         test_buf<char> f;
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|         assert(f.open("underflow.dat", std::ios_base::in | std::ios_base::out) != 0);
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|         assert(f.is_open());
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|         assert(f.sbumpc() == '1');
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|         assert(f.sgetc() == '2');
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|         assert(f.pbackfail('a') == 'a');
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|         assert(f.sbumpc() == 'a');
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|         assert(f.sgetc() == '2');
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|     }
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| }
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