How can I read the entire stream into std :: vector?
I read the answer here which shows how to read an entire stream into a std :: string with the following (two) liners:
std::istreambuf_iterator<char> eos;
std::string s(std::istreambuf_iterator<char>(stream), eos);
To do something similar to reading a binary stream in std::vector
, why can't I just replace char
with uint8_t
and std::string
with std::vector
?
auto stream = std::ifstream(path, std::ios::in | std::ios::binary);
auto eos = std::istreambuf_iterator<uint8_t>();
auto buffer = std::vector<uint8_t>(std::istreambuf_iterator<uint8_t>(stream), eos);
The above compiler error (VC2013):
1> d: \ non-svn \ C ++ \ library \ i \ file \ filereader.cpp (62): error C2440: ': cannot convert from' std :: basic_ifstream> 'to' std :: istreambuf_iterator> '1 >
with 1> [1> _Elem = uint8_t 1>] 1>
Constructor cannot use source type or constructor overload resolution was ambiguous
source to share
There's just a type mismatch. ifstream
is just a typedef:
typedef basic_ifstream<char> ifstream;
So, if you want to use a different base type, just tell it:
std::basic_ifstream<uint8_t> stream(path, std::ios::in | std::ios::binary);
auto eos = std::istreambuf_iterator<uint8_t>();
auto buffer = std::vector<uint8_t>(std::istreambuf_iterator<uint8_t>(stream), eos);
This works for me.
Or, since Dietmar says it might be a little sketchy, you can do something like:
auto stream = std::ifstream(...);
std::vector<uint8_t> data;
std::for_each(std::istreambuf_iterator<char>(stream),
std::istreambuf_iterator<char>(),
[&data](const char c){
data.push_back(c);
});
source to share
ifstream
- flow char
, not uint8_t
. You will need basic_ifstream<uint8_t>
or istreambuf_iterator<char>
for the respective types.
The former may not work without some work, since the library is only required to support threads char
and wchar_t
; so you probably want istreambuf_iterator<char>
.
source to share