std::basic_ifstream::basic_ifstream
From cppreference.com
< cpp | io | basic ifstream
basic_ifstream();
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(1) | |
explicit basic_ifstream( const char* filename,
ios_base::openmode mode = ios_base::in ); |
(2) | |
explicit basic_ifstream( const string& filename,
ios_base::openmode mode = ios_base::in ); |
(3) | (since C++11) |
basic_ifstream( basic_ifstream&& other );
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(4) | (since C++11) |
basic_ifstream( const basic_ifstream& rhs) = delete;
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(5) | (since C++11) |
Constructs new file stream.
1) Default constructor: constructs a stream that is not associated with a file: default-constructs the std::basic_filebuf and constructs the base with the pointer to this default-constructed std::basic_filebuf member.
2) First, performs the same steps as the default constructor, then associates the stream with a file by calling rdbuf()->open(filename, mode | std::ios_base::in). If the open() call returns a null pointer, sets setstate(failbit).
3) Same as basic_ifstream(filename.c_str(), mode).
4) Move constructor. First, move-constructs the base class from
other
(which does not affect the rdbuf()
pointer), then move-constructs the std::basic_filebuf member, then calls this->set_rdbuf() to install the new basic_filebuf
as the rdbuf() pointer in the base class.
5) The copy-constructor is deleted: this class is not copyable.
[edit] Parameters
filename | - | the name of the file to be opened | ||||||||||||||
mode | - | specifies stream open mode. It is bitmask type, the following constants are defined:
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other | - | another file stream to use as source |
[edit] Example
Run this code
#include <fstream> #include <utility> #include <string> int main() { std::ifstream f0; std::ifstream f1("test.bin", std::ios::binary); std::string name = "example.txt"; std::ifstream f2(name); std::ifstream f3(std::move(f1)); }
[edit] See also
opens a file and associates it with the stream (public member function) |
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opens a file and configures it as the associated character sequence (public member function of std::basic_filebuf )
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replaces the rdbuf without clearing its error state (protected member function) |
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constructs the object (public member function of std::basic_istream )
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