What the fastest way to copy strings from file to a vector in STL? 7 2207
"SIgnOff" <Si*****@gala.n et> wrote... What the fastest way to copy strings from file to a vector in STL?
In what sense "fastest"? And a vector of what? Assuming certain things,
one could write
std::vector<std ::string> vs;
std::string somestring;
std::ifstream somefile("somef ilename");
while (std::getline(s omefile, somestring))
vs.push_back(so mestring);
V
Victor Bazarov wrote: "SIgnOff" <Si*****@gala.n et> wrote...
What the fastest way to copy strings from file to a vector in STL?
In what sense "fastest"? And a vector of what? Assuming certain things, one could write
std::vector<std ::string> vs; std::string somestring; std::ifstream somefile("somef ilename"); while (std::getline(s omefile, somestring)) vs.push_back(so mestring);
Oh, come on, Victor, you're not going to use an istream_iterato r? :-)
std::vector<std ::string> vs;
std::ifstream somefile("somef ilename");
std::copy(std:: istream_iterato r<std::string>( somefile),
std::istream_it erator<std::str ing>(),
std::back_inser ter(vs));
red floyd wrote:
[ ... ] std::vector<std ::string> vs; std::string somestring; std::ifstream somefile("somef ilename"); while (std::getline(s omefile, somestring)) vs.push_back(so mestring);
Oh, come on, Victor, you're not going to use an istream_iterato r? :-)
std::vector<std ::string> vs; std::ifstream somefile("somef ilename"); std::copy(std:: istream_iterato r<std::string>( somefile), std::istream_it erator<std::str ing>(), std::back_inser ter(vs));
Note that these do _completely_ different things. Victor's code reads
each _line_ in the input into a string. Your code reads each _word_
into its own string.
--
Later,
Jerry.
The universe is a figment of its own imagination.
Jerry Coffin wrote: red floyd wrote:
[ ... ]
std::vector<std ::string> vs; std::string somestring; std::ifstream somefile("somef ilename"); while (std::getline(s omefile, somestring)) vs.push_back(so mestring);
Oh, come on, Victor, you're not going to use an istream_iterato r? :-)
std::vector<s td::string> vs; std::ifstre am somefile("somef ilename"); std::copy(std ::istream_itera tor<std::string >(somefile), std::istream_it erator<std::str ing>(), std::back_inser ter(vs));
Note that these do _completely_ different things. Victor's code reads each _line_ in the input into a string. Your code reads each _word_ into its own string.
Good point. You're absolutely right. However, the original post
said "read strings into a vector". Either approach could be correct,
but I suspect OP meant newline delimited. So I concede the point.
I guess if you wanted to use the std::copy method, you'd have to define
a proxy class with operator >> that read an entire line, and also had an
"operator std::string() const" method. At which point we've long since
passed the point of diminishing returns.
red floyd wrote:
[ ... ] Note that these do _completely_ different things. Victor's code reads each _line_ in the input into a string. Your code reads each _word_ into its own string.
Good point. You're absolutely right. However, the original post said "read strings into a vector". Either approach could be correct, but I suspect OP meant newline delimited. So I concede the point.
No point to concede, IMO. I wasn't trying to say either was right or
wrong, just that they're not the same. I don't think the OP provided
enough information to indicate which is desired.
I guess if you wanted to use the std::copy method, you'd have to define a proxy class with operator >> that read an entire line, and also had an "operator std::string() const" method. At which point we've long since passed the point of diminishing returns.
There's another possibility -- imbue the stream with a locale that
defines the newline as its only space character. I'd tend to agree that
neither of these is practical unless you use them considerably more
than once.
--
Later,
Jerry.
The universe is a figment of its own imagination.
These codes widely well-known both.
Is any other fast ways?
-----------------
std::vector<std ::string> vs;
std::ifstream somefile("somef ilename");
std::copy(std:: istream_iterato r<std::string>( somefile),
std::istream_it erator<std::str ing>(),
std::back_inser ter(vs));
---------------
std::vector<std ::string> vs;
std::string somestring;
std::ifstream somefile("somef ilename");
while (std::getline(s omefile, somestring))
vs.push_back(so mestring); This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics |
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