This is a mirror of my library hosted at https://create.stephan-brumme.com/portable-memory-mapping/

Portable Memory Mapping C++ Class

Memory mapping is one of the nicest features of modern operating systems: after opening a file in memory-mapped mode you can treat the file as a large chunk of memory and use plain pointers. The operating system takes care of loading the data on demand (!) into memory - utilizing caches, of course.

When using my C++ class MemoryMapped it's really easy:

// open file
MemoryMapped data("myfile.txt");

// read byte at file offset 2345
unsigned char a = data[2345];

// or if you prefer pointers
const short* raw = (const short*) data.getData();
short        b   = raw[300];

Windows is completely different from Linux when it comes to opening a file in memory-mapped mode. The class MemoryMapped hides all the OS specific stuff in only two files: MemoryMapped.h and MemoryMapped.cpp. They compile without any warning with GCC and Visual C++.