Home / Forums / Fast Compile-Time String Hashing with C++17 constexpr [Discussion #9]

Source

Fast Compile-Time String Hashing with C++17 constexpr [Discussion #9]

Unity & IL2CPP Reverser

VIP

Rep: 295

Join Date: Nov 2022

Posts: 32

Thanks: 74

5y ago · Feb 4, 2021 8:09 PM

Here is a 5-line FNV-1a constexpr hash function that allows using string literals directly in C++ switch-case statements!

RustMechanic | IL2CPP & Unity Engine Analysis

The following users thanked RustMechanic for this post:

Kernel & Systems Researcher

VIP

Rep: 275

Join Date: Jan 2024

Posts: 24

Thanks: 70

5y ago · Feb 4, 2021 10:40 PM

Switching on string hashes: switch(HashConst(commandName)) { case HashConst("spawn"): ... } makes text dispatchers O(1) jump tables!

KernelDiver · Windows Internals & Page Tables

DirectX 12 / Vulkan Dev

MEMBER

Rep: 240

Join Date: Feb 2023

Posts: 31

Thanks: 60

5y ago · Feb 6, 2021 2:40 AM

Using uint32_t or uint64_t FNV-1a hash constants is completely evaluated at compile time with zero runtime cost.

DirectXRay · DirectX 12 & Vulkan Command Lists

Destination Subforum

Thread Prefix

Thread Title

Post Content (BBCode Enabled)

File Attachment

UnreliableCode Community