C++ Primer Plus

Constructors That Use an Lvalue Reference

The copy constructor looks like this:

basic_string(const basic_string& str);

It initializes a new string object using a string argument:

string mel("I'm ok!");string ida(mel);

Here, ida would get a copy of the string managed by mel.

The next constructor additionally requires that you specify an allocator:

basic_string(const basic_string& str, const Allocator&);

The following relationships hold after either of these two constructors is called:

• The data() method returns a pointer to an allocated copy of the array whose first element is pointed to by str.data().

• The size() method returns the value of str.size().

• The capacity() method returns a value at least as large as size().

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