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# C++ concepts: CopyConstructible

From cppreference.com
< cpp‎ | concept

Specifies that an instance of the type can be copy-constructed from an lvalue expression.

### [edit] Requirements

The type `T` satisfies `CopyConstructible` if

- The type `T` satisfies `MoveConstructible`, and

Given

- `v`, an lvalue expression of type `T` or `const T` or an rvalue expression of type `const T`
- `u`, an arbitrary identifier

The following expressions must be valid and have their specified effects

Expression | Post-conditions
--- | ---
T u = v; | The value of `u` is equivalent to the value of `v`. The value of `v` is unchanged
T(v) | The value of `T(v)` is equivalent to the value of `v`. The value of `v` is unchanged.

The expression v.~T() also must be valid, and, for lvalue `v`, the expression `&v` must have the type T* or const T* and must evaluate to the address of `v` | (until C++11)

### [edit] Notes

Until C++11, classes that overloaded `operator&` were not `CopyConstructible` and thus weren't usable in the standard library containers. As of C++11, the standard library uses std::addressof whenever the address of an object is needed.

### [edit] See also

is_copy_constructible is_trivially_copy_constructible is_nothrow_copy_constructible (C++11)(C++11)(C++11) | checks if a type has a copy constructor (class template) [edit]

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