TLDR; from 2005 up to 2018/Git 2.18: SHA-1 (see below) 2019, will switch at some point to SHA-256 You can check that from Linus Torvalds himself, when he presented Git to Google back in 2007: (emphasis mine) We check checksums that is considered cryptographically secure. Nobody has been able to break SHA-1, but the point … Read more
This is an unfortunate omission in C++11; Boost has the answer in terms of hash_combine. Feel free to just paste it from them! Here’s how I hash pairs: template <class T> inline void hash_combine(std::size_t & seed, const T & v) { std::hash<T> hasher; seed ^= hasher(v) + 0x9e3779b9 + (seed << 6) + (seed >> … Read more
A hashmap works like this (this is a little bit simplified, but it illustrates the basic mechanism): It has a number of “buckets” which it uses to store key-value pairs in. Each bucket has a unique number – that’s what identifies the bucket. When you put a key-value pair into the map, the hashmap will … Read more