使用 std::string 聲明一個 std::bitset 數組

Question

我目前正在嘗試聲明一個包含 17 個 std::bitsets 的數組，每個 32 位長。 我這樣做是這樣的：

std::bitset<32> mTestInstruction[17]
{
    std::string("01000000001000000000000000000001"),
    std::string("01000000011000000000000001100011"),
    std::string("01000000101000000000000000000001"),
    std::string("10100000000000000000000000001010"),
    std::string("00000000100000010000000010000010"),
    std::string("00000000110001010010000000000001"),
    std::string("01001000111001010000000000000000"),
    std::string("01000100001000110000000000000011"),
    std::string("01000000001000010000000000000001"),
    std::string("10000000000000000000000000000011"),
    std::string("00000000010000000000000000000001"),
    std::string("00000000111000000000000000000001"),
    std::string("00000000111001110000100000000001"),
    std::string("01000000010000100000000000000001"),
    std::string("01000100001000100000000000000010"),
    std::string("10000000000000000000000000001100"),
    std::string("11100000000000000000000000001000"),
};

我收到以下錯誤：

error: could not convert 'std::__cxx11::basic_string<char>(((const char*)"01000000001000000000000000000001"), std::allocator<char>())' from 'std::__cxx11::string {aka std::__cxx11::basic_string<char>}' to 'std::bitset<32u>'

對於每個位串。

我不明白為什么會發生這種情況，因為根據 cpp 參考 std::string 是構造位集的有效方法。 誰能指出如何解決這個問題？

Answer 1

您需要調用std::bitset的構造函數，例如：

std::bitset< 32 > mTestInstruction[17]
{
    std::bitset< 32 >( std::string( "01000000001000000000000000000001" ) ),
    std::bitset< 32 >( std::string( "01000000011000000000000001100011" ) ),
    // ...
};

甚至更短：

std::bitset< 32 > mTestInstruction[17]
{
    std::bitset< 32 >( "01000000001000000000000000000001" ),
    std::bitset< 32 >( "01000000011000000000000001100011" ),
    // ...
};

您的代碼不起作用的原因是因為std::bitset接受std::string的構造函數被標記為顯式（請參見此處）。

從 C++14 您可以使用二進制文字，例如：

std::bitset< 32 > mTestInstruction[17]
{
    0b01000000001000000000000000000001,
    0b01000000011000000000000001100011,
    // ...
};

Answer 2

你可以這樣做：

std::bitset<32> mTestInstruction[17]{
        std::bitset<32>{std::string("01000000001000000000000000000001")},
        std::bitset<32>{std::string("01000000011000000000000001100011")},
        std::bitset<32>{std::string("01000000101000000000000000000001")},
        std::bitset<32>{std::string("10100000000000000000000000001010")},
        std::bitset<32>{std::string("00000000100000010000000010000010")},
        std::bitset<32>{std::string("00000000110001010010000000000001")},
        std::bitset<32>{std::string("01001000111001010000000000000000")},
        std::bitset<32>{std::string("01000100001000110000000000000011")},
        std::bitset<32>{std::string("01000000001000010000000000000001")},
        std::bitset<32>{std::string("10000000000000000000000000000011")},
        std::bitset<32>{std::string("00000000010000000000000000000001")},
        std::bitset<32>{std::string("00000000111000000000000000000001")},
        std::bitset<32>{std::string("00000000111001110000100000000001")},
        std::bitset<32>{std::string("01000000010000100000000000000001")},
        std::bitset<32>{std::string("01000100001000100000000000000010")},
        std::bitset<32>{std::string("10000000000000000000000000001100")},
        std::bitset<32>{std::string("11100000000000000000000000001000")},
    };