emadflash

How to add an image to a gist

1. Create a gist if you haven't already.
2. Clone your gist:

   # make sure to replace `<hash>` with your gist's hash
   git clone https://gist.github.com/<hash>.git # with https
   git clone git@gist.github.com:<hash>.git     # or with ssh

emadflash

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

emadflash

from sqlalchemy import Column, Integer, String, ForeignKey, create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import relationship, backref, sessionmaker, joinedload

# For this example we will use an in-memory sqlite DB.
# Let's also configure it to echo everything it does to the screen.
engine = create_engine('sqlite:///:memory:', echo=True)

# The base class which our objects will be defined on.
Base = declarative_base()

emadflash

tmux cheatsheet

As configured in my dotfiles.

start new:

tmux

start new with session name: