“CopyConstructible” requirement for C++ stl container element

Question

Regarding to the requirement for C++ stl container element, the standard says: the element type should be CopyConstructible, and there is a table for CopyConstructible requi

Answer 1

Related post: What is the difference between equality and equivalence?

Edited to make this a "non comment".

Equivalence means "equal for all intents and purposes". For example: 1.0001 and 1 are never equal, but under certain circumstances they are equivalent. This is the general answer.

What the books mean are that the copied objects must satisfy the strict weak ordering condition with the original object: copy < original == false && original < copy == false.