There's a binary file words.bin
containing multiple 4 byte integers. I want to read them from the file into a std::vector
of corresponding size, which is uint32_t
. Here's what I've tried first:
#include <fstream>
#include <iterator>
#include <vector>
#include <cstdint>
int main(int argc, char* argv[])
{
std::ifstream f("words.bin", std::ios::in | std::ios::binary);
std::vector<uint32_t> wordvec(std::istreambuf_iterator<uint32_t>{f}, {});
return 0;
}
However, I get this error message:
u32vec.cpp: In function 'int main(int, char**)':
u32vec.cpp:9:71: error: no matching function for call to 'std::istreambuf_iterator<unsigned int>::istreambuf_iterator(<brace-enclosed initializer list>)'
std::vector<uint32_t> wordvec(std::istreambuf_iterator<uint32_t>{f}, {});
If I change both uint32_t
to char
, it does work, but this is not what I want.
My second try was writing the curly bracket notation explicitly, but then accessing the methods of std::vector
gives a syntax error. This is the code:
#include <fstream>
#include <iterator>
#include <vector>
#include <cstdint>
int main(int argc, char* argv[])
{
std::ifstream f("words.bin", std::ios::in | std::ios::binary);
std::vector<uint32_t> wordvec(std::istreambuf_iterator<uint32_t>(f), std::istreambuf_iterator<uint32_t>());
wordvec.at(0);
return 0;
}
And this is the compiler output:
u32vec.cpp: In function 'int main(int, char**)':
u32vec.cpp:11:13: error: request for member 'at' in 'wordvec', which is of non-class type 'std::vector<unsigned int>(std::istreambuf_iterator<unsigned int>, std::istreambuf_iterator<unsigned int> (*)())'
wordvec.at(0);
^~
This is the output of g++ --version
:
g++ (x86_64-posix-seh-rev0, Built by MinGW-W64 project) 8.1.0
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.