cuda::always_true and cuda::always_false

Defined in the header <cuda/functional>.

struct always_true {
    template <typename... Ts>
    [[nodiscard]] __host__ __device__ constexpr bool operator()(Ts&&...) const noexcept;
};

struct always_false {
    template <typename... Ts>
    [[nodiscard]] __host__ __device__ constexpr bool operator()(Ts&&...) const noexcept;
};

cuda::always_true is a function object that always returns true regardless of the number and type of arguments passed. cuda::always_false is a function object that always returns false regardless of the number and type of arguments passed.

Both types are empty, trivially copyable, and their operator() is constexpr and noexcept.

Example

#include <cuda/functional>

__global__ void example_kernel() {
    cuda::always_true  pred_true{};
    cuda::always_false pred_false{};

    // Returns true regardless of arguments
    static_assert(pred_true());
    static_assert(pred_true(1, 2, 3));

    // Returns false regardless of arguments
    static_assert(!pred_false());
    static_assert(!pred_false(1, 2, 3));
}