Frictionless Allocators

This talk examines the complexity of writing allocator-aware C++ libraries and proposes language extensions to simplify allocator support. It also discusses an early prototype and how to assess the proposals’ readiness for standardization.

Syllabus

Intro
Outline of Talk
What is an allocator?
Why Do We Want Allocators?
A Faster Allocator
Performance
Special Memory
Emery Berger
Accelerating Programs via Custom Allocators
Initial empirical results
Early Results
Allocator Traits (since 2011)
How does pmr work?
memory_resource
Standard Resources
Idiom and usage of pm
Quick Example
Scoped Allocator Model
Limitations of pmr
Bloomberg Experience
Unsupported use cases
Allocator Propagation
Complexity of Propagation
Syntactic overhead is high
Copy Constructor Issue
Ideal Model
Allocator Awareness
Why Implicit from Members?
Why querying matters
Simplifying Construction
Worked Example
Implementing Awareness
Implicit Awareness
Allocator Injection