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Michael Ellery mellery451

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@rendello
rendello / _utf8_case_data.rs
Last active March 11, 2025 21:53
Unicode codepoints that expand or contract when case is changed in UTF-8. Good for testing parsers. Includes the data `utf8_case_data.rs` and the script to generate it, `generate_utf8.py`.
/*
Copyright (c) 2024 Rendello
Permission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
@htfy96
htfy96 / cpp-build-profile-2024.md
Last active November 8, 2024 18:30
C++ Build profiles for 2024 projects

C++ Build profiles for 2024 projects

Standard development profile

This profile achieves 50% - 80% release profile performance, while also provides a reasonable amount of safety checks and debugging support. This should also be the profile for your CI build.

Compilation flags

-Og -Wall -Wextra -D_FORTIFY_SOURCE=2 -fstack-protector-strong -g -D_GLIBCXX_ASSERTIONS
@shafik
shafik / WhatIsStrictAliasingAndWhyDoWeCare.md
Last active April 26, 2025 00:19
What is Strict Aliasing and Why do we Care?

What is the Strict Aliasing Rule and Why do we care?

(OR Type Punning, Undefined Behavior and Alignment, Oh My!)

What is strict aliasing? First we will describe what is aliasing and then we can learn what being strict about it means.

In C and C++ aliasing has to do with what expression types we are allowed to access stored values through. In both C and C++ the standard specifies which expression types are allowed to alias which types. The compiler and optimizer are allowed to assume we follow the aliasing rules strictly, hence the term strict aliasing rule. If we attempt to access a value using a type not allowed it is classified as undefined behavior(UB). Once we have undefined behavior all bets are off, the results of our program are no longer reliable.

Unfortunately with strict aliasing violations, we will often obtain the results we expect, leaving the possibility the a future version of a compiler with a new optimization will break code we th