hash< OpenMS::EmpiricalFormula > Struct Reference

Hash function for OpenMS::EmpiricalFormula. More...

#include <OpenMS/CHEMISTRY/EmpiricalFormula.h>

Public Member Functions
std::size_t	operator() (const OpenMS::EmpiricalFormula &ef) const noexcept

Detailed Description

Hash function for OpenMS::EmpiricalFormula.

Computes a hash based on element symbols and their counts, plus the charge. The hash is consistent with operator==.

Design decisions:

• Uses element symbols (not pointers) to distinguish isotopes like (13)C vs C
• Sorts elements by symbol for reproducible hash across runs
• FNV-1a based combining for good distribution

Note

Hash is reproducible across process runs on the same platform.

Member Function Documentation

operator()()

std::size_t operator() ( const OpenMS::EmpiricalFormula &  ef ) const

inlinenoexcept

References OpenMS::fnv1a_hash_string(), OpenMS::hash_combine(), and OpenMS::hash_int().