namespace boost {
namespace lambda2 {

// placeholders

template<int I> struct lambda2_arg;

inline constexpr lambda2_arg<1> _1{};
inline constexpr lambda2_arg<2> _2{};
inline constexpr lambda2_arg<3> _3{};
inline constexpr lambda2_arg<4> _4{};
inline constexpr lambda2_arg<5> _5{};
inline constexpr lambda2_arg<6> _6{};
inline constexpr lambda2_arg<7> _7{};
inline constexpr lambda2_arg<8> _8{};
inline constexpr lambda2_arg<9> _9{};

// arithmetic operators

template<class A, class B> auto operator+( A && a, B && b );
template<class A, class B> auto operator-( A && a, B && b );
template<class A, class B> auto operator*( A && a, B && b );
template<class A, class B> auto operator/( A && a, B && b );
template<class A, class B> auto operator%( A && a, B && b );
template<class A> auto operator-( A && a );

// relational operators

template<class A, class B> auto operator==( A && a, B && b );
template<class A, class B> auto operator!=( A && a, B && b );
template<class A, class B> auto operator>( A && a, B && b );
template<class A, class B> auto operator<( A && a, B && b );
template<class A, class B> auto operator>=( A && a, B && b );
template<class A, class B> auto operator<=( A && a, B && b );

// logical operators

template<class A, class B> auto operator&&( A && a, B && b );
template<class A, class B> auto operator||( A && a, B && b );
template<class A> auto operator!( A && a );

// bitwise operators

template<class A, class B> auto operator&( A && a, B && b );
template<class A, class B> auto operator|( A && a, B && b );
template<class A, class B> auto operator^( A && a, B && b );
template<class A> auto operator~( A && a );

template<class A, class B> auto operator<<( A && a, B && b );
template<class A, class B> auto operator>>( A && a, B && b );

// additional unary operators

template<class A> auto operator+( A && a );
template<class A> auto operator*( A && a );
template<class A> auto operator++( A && a );
template<class A> auto operator--( A && a );
template<class A> auto operator++( A && a, int );
template<class A> auto operator--( A && a, int );

// compound assignment operators

template<class A, class B> auto operator+=( A && a, B && b );
template<class A, class B> auto operator-=( A && a, B && b );
template<class A, class B> auto operator*=( A && a, B && b );
template<class A, class B> auto operator/=( A && a, B && b );
template<class A, class B> auto operator%=( A && a, B && b );
template<class A, class B> auto operator&=( A && a, B && b );
template<class A, class B> auto operator|=( A && a, B && b );
template<class A, class B> auto operator^=( A && a, B && b );
template<class A, class B> auto operator<<=( A && a, B && b );
template<class A, class B> auto operator>>=( A && a, B && b );

// additional binary operators

template<class A, class B> auto operator->*( A && a, B && b );

// projections

inline constexpr /unspecified/ first{};
inline constexpr /unspecified/ second{};

} // namespace lambda2
} // namespace boost