c - Visual Studio 相当于 Arm #pragma anon_unions

Question

Arm“#pragma anon_unions”允许:

typedef struct {
    uint32_t sensorID;
    uint8_t  messageHeader;
    uint8_t  messageID;
    uint16_t payloadLength;
} Header;

typedef struct {
    uint8_t startOfPacket[SERIAL_SOP_SIZE]; 
    Header; // Anonymous.
    uint8_t payload[SIZE];
} Packet;

Packet packet;
packet.messageID = 1; // Referencing member of Header through a Packet.

关于在 VisualStudio 中编译此代码有什么想法吗？

Answer 1

它可以在 Visual C++ 中编译，但是 only in C mode :

A Microsoft C extension allows you to declare a structure variable within another structure without giving it a name. These nested structures are called anonymous structures. C++ does not allow anonymous structures.