Efficiently reading a very large text file in C++

Question

I have a very large text file(45GB). Each line of the text file contains two space separated 64bit unsigned integers as shown below.

4624996948753406865 10214715013

Answer 1

You can memory map the file into memory, but that would be platform dependent (on unix that would be mmap on windows CreateFileMapping/MapViewIntoFile); still if in 32 bit system you may have problems if there is not a big enough virtual memory block left (64 bit systems would not have that problem).

Memory mapping is supposed to be faster than reading the data block by block from disk.