Question

I want to write a dynamic pointer to a file in C++.

This is my declaration in header file:

byte* buffer;

Then in Cpp file, I allocated it:

buffer = new byte[1000];

However the size will be bigger than 1000 in dynamic allocation.

Then I write to the file:

ofstream myfile;

myfile.open("test.txt", ios::binary);
myfile.write((char*)buffer, 1000);  
myfile.close();

If I specify the length of buffer to 1000, then the rest of bytes after 1000 will be discarded. If I use: sizeof(buffer) then it is only 1 byte written.

How can I get the dynamic size of the buffer?

Answer 1

Simple:

std::vector<byte> buffer;
buffer.resize(1000);
myfile.write(&buffer[0], buffer.size());