Program Listing for File ConstantTestHelpers.hpp

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// Copyright 2018-2023 Xanadu Quantum Technologies Inc.

// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at

//     http://www.apache.org/licenses/LICENSE-2.0

// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#pragma once

#include "TypeTraits.hpp"
#include "Util.hpp"

#include <algorithm>
#include <array>
#include <compare>
#include <cstdlib>
#include <stdexcept>

#if __has_include(<version>)
#include <version>
#endif

namespace Pennylane::LightningQubit::Util {
template <typename T, typename U, std::size_t size>
constexpr std::array<T, size>
first_elems_of(const std::array<std::pair<T, U>, size> &arr) {
    std::array<T, size> res = {
        T{},
    };
    std::transform(arr.begin(), arr.end(), res.begin(),
                   [](const auto &elem) { return std::get<0>(elem); });
    return res;
}
template <typename T, typename U, std::size_t size>
constexpr std::array<U, size>
second_elems_of(const std::array<std::pair<T, U>, size> &arr) {
    std::array<U, size> res = {
        U{},
    };
    std::transform(arr.begin(), arr.end(), res.begin(),
                   [](const auto &elem) { return std::get<1>(elem); });
    return res;
}

template <typename T, std::size_t size>
constexpr std::size_t count_unique(const std::array<T, size> &arr) {
    std::size_t res = 0;

    for (size_t i = 0; i < size; i++) {
        bool counted = false;
        for (size_t j = 0; j < i; j++) {
            if (arr[j] == arr[i]) {
                counted = true;
                break;
            }
        }
        if (!counted) {
            res++;
        }
    }
    return res;
}

#if __cpp_lib_three_way_comparison >= 201907L
template <std::three_way_comparable T, std::size_t size>
constexpr std::size_t count_unique(const std::array<T, size> &arr) {
    auto arr_cpd = arr;
    std::size_t dup_cnt = 0;
    std::sort(std::begin(arr_cpd), std::end(arr_cpd));
    for (size_t i = 0; i < size - 1; i++) {
        if (arr_cpd[i] == arr_cpd[i + 1]) {
            dup_cnt++;
        }
    }
    return size - dup_cnt;
}
#endif

} // namespace Pennylane::LightningQubit::Util

api/program_listing_file_pennylane_lightning_core_src_utils_ConstantTestHelpers.hpp

 

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