I want to create a std::ifstream using std::string

[Assertor]

Hi, all.

Is there any way to create an instance of std::ifstream using
std::string.
(through std::ifstream's constructor or assignment operator or
iterator, etc...)

i.e.
std::string str = "this is a string";
std::ifstream ifs = str; //<----- this is a just pseudo code.

(^^;; I can solve this using making temporty file and write the str on
the file and reading it using std::ifstream...
but I don't want to make a additional file io ^^)

plz show me the way~

 

[Alf P. Steinbach]

* Assertor:

Is there any way to create an instance of std::ifstream using
std::string.
(through std::ifstream's constructor or assignment operator or
iterator, etc...)

i.e.
std::string str = "this is a string";
std::ifstream ifs = str; //<----- this is a just pseudo code.

(^^;; I can solve this using making temporty file and write the str on
the file and reading it using std::ifstream...
but I don't want to make a additional file io ^^)

Why don't you use a std::istringstream.

 

[whunmr]

Hi, all.

how about this follow?

std::string str = "this is a string";
std::ifstream ifs(str.c_str());

 

[Zeppe]

how about this follow?

std::string str = "this is a string";
std::ifstream ifs(str.c_str());

this is a bad error, because in this case str is taken as a filename.

Regards,

Zeppe

 

[James Kanze]

Is there any way to create an instance of std::ifstream using
std::string.
(through std::ifstream's constructor or assignment operator or
iterator, etc...)

i.e.
std::string str = "this is a string";
std::ifstream ifs = str; //<----- this is a just pseudo code.

(^^;; I can solve this using making temporty file and write the str on
the file and reading it using std::ifstream...
but I don't want to make a additional file io ^^)

Why do you want to do this? Normally, except for creation, you
should be using the istream interface (from the base class).
And of course, this works just as well with an istringstream as
with an ifstream.

 

[BobR]

Zeppe wrote in message...

this is a bad error, because in this case str is taken as a filename.
Regards,
Zeppe

{
std::string str = "\"this is a string\"";
std::ifstream ifs( str.c_str() );
ifs << str << std::endl;
}

There! All fixed.
<G>

note: On some systems you need to put the filename in quotes if there are
spaces in the filename.