[string.op.plus] (original) (raw)

21 Strings library [strings]

21.3 String classes [string.classes]

21.3.3 Non-member functions [string.nonmembers]

21.3.3.1 operator+ [string.op.plus]

template<class charT, class traits, class Allocator> constexpr basic_string<charT, traits, Allocator> operator+(const basic_string<charT, traits, Allocator>& lhs,const basic_string<charT, traits, Allocator>& rhs);template<class charT, class traits, class Allocator> constexpr basic_string<charT, traits, Allocator> operator+(const basic_string<charT, traits, Allocator>& lhs, const charT* rhs);

Effects:Equivalent to:

basic_string<charT, traits, Allocator> r = lhs; r.append(rhs); return r;

template<class charT, class traits, class Allocator> constexpr basic_string<charT, traits, Allocator> operator+(basic_string<charT, traits, Allocator>&& lhs,const basic_string<charT, traits, Allocator>& rhs);template<class charT, class traits, class Allocator> constexpr basic_string<charT, traits, Allocator> operator+(basic_string<charT, traits, Allocator>&& lhs, const charT* rhs);

Effects:Equivalent to:

lhs.append(rhs); return std::move(lhs);

template<class charT, class traits, class Allocator> constexpr basic_string<charT, traits, Allocator> operator+(basic_string<charT, traits, Allocator>&& lhs, basic_string<charT, traits, Allocator>&& rhs);

Effects:Equivalent to:

lhs.append(rhs); return std::move(lhs);

except that both lhs and rhsare left in valid but unspecified states.

[ Note

:

If lhs and rhs have equal allocators, the implementation may move from either.

end note

]

template<class charT, class traits, class Allocator> constexpr basic_string<charT, traits, Allocator> operator+(const basic_string<charT, traits, Allocator>& lhs, basic_string<charT, traits, Allocator>&& rhs);template<class charT, class traits, class Allocator> constexpr basic_string<charT, traits, Allocator> operator+(const charT* lhs, basic_string<charT, traits, Allocator>&& rhs);

Effects:Equivalent to:

rhs.insert(0, lhs); return std::move(rhs);

template<class charT, class traits, class Allocator> constexpr basic_string<charT, traits, Allocator> operator+(const charT* lhs, const basic_string<charT, traits, Allocator>& rhs);

Effects:Equivalent to:

basic_string<charT, traits, Allocator> r = rhs; r.insert(0, lhs); return r;

template<class charT, class traits, class Allocator> constexpr basic_string<charT, traits, Allocator> operator+(charT lhs, const basic_string<charT, traits, Allocator>& rhs);

Effects:Equivalent to:

basic_string<charT, traits, Allocator> r = rhs; r.insert(r.begin(), lhs); return r;

template<class charT, class traits, class Allocator> constexpr basic_string<charT, traits, Allocator> operator+(charT lhs, basic_string<charT, traits, Allocator>&& rhs);

Effects:Equivalent to:

rhs.insert(rhs.begin(), lhs); return std::move(rhs);

template<class charT, class traits, class Allocator> constexpr basic_string<charT, traits, Allocator> operator+(const basic_string<charT, traits, Allocator>& lhs, charT rhs);

Effects:Equivalent to:

basic_string<charT, traits, Allocator> r = lhs; r.push_back(rhs); return r;

template<class charT, class traits, class Allocator> constexpr basic_string<charT, traits, Allocator> operator+(basic_string<charT, traits, Allocator>&& lhs, charT rhs);

Effects:Equivalent to:

lhs.push_back(rhs); return std::move(lhs);