Stack

Stack - PUSH/POP

LIFO stack

Stacks are a type of container adaptors, specifically designed to operate in a LIFO context (last-in first-out), where elements are inserted and extracted only from the end of the container.

stacks are implemented as containers adaptors, which are classes that use an encapsulated object of a specific container class as its underlying container, providing a specific set of member functions to access its elements. Elements are pushed/popped from the “back” of the specific container, which is known as the top of the stack.

The underlying container may be any of the standard container class templates or some other specifically designed container class. The only requirement is that it supports the following operations:

• back()
• push_back()
• pop_back()

Link:

http://www.cplusplus.com/reference/stl/stack/

http://en.wikipedia.org/wiki/Stack_(data_structure)

Asserts

 

Assert Safely

 

Expert programmers use the assert() macro to seed their code with debugging statements. So should we all.

The macro must have no effect on the system – it shouldn’t change memory, interrupt state, or I/O, and it should make no function calls. The user must feel free to sprinkle these at will throughout the program. Disabling the asserts in released code must never change the way the program operates.

The macro generally looks something like:

#define
assert(s)
if (s)
{}else (printf("Error at %s %d: ", __FILE__, __LINE__)

It’s sort of an odd way to write code – if the condition is true (in which case assert() takes no action) there’s a null pair of braces. Why not test the negation of the statement “s”?

Links: http://www.ganssle.com/articles/adifasts.htm