结构初始化警告

Question

我有这个结构：

struct ChangeIntItem
{
    char *unit;
    const char **parser;
    int *changevalue;
    uint16_t *change_eeprom_value;
    int maximum;
    int minimum;
};

我想用这个结构变量初始化其他变量：

struct ChangeIntItem ChangeIntItemTypeBoolean = { .unit = "", .minimum = 0, .maximum = 1, .parser = {"off", "on"}};

它工作正常，但我收到一些警告：

Severity    Code    Description Project File    Line
Warning     braces around scalar initializer    Handsteuerung   C:\Users\...    11

Severity    Code    Description Project File    Line
Warning     (near initialization for 'ChangeIntItemTypeBoolean.parser') Handsteuerung   C:\Users\...    11

Severity    Code    Description Project File    Line
Warning     initialization from incompatible pointer type   Handsteuerung   C:\Users\...    11

Severity    Code    Description Project File    Line
Warning     (near initialization for 'ChangeIntItemTypeBoolean.parser') Handsteuerung   C:\Users\...    11

Severity    Code    Description Project File    Line
Warning     excess elements in scalar initializer   Handsteuerung   C:\Users\...    11

Severity    Code    Description Project File    Line
Warning     (near initialization for 'ChangeIntItemTypeBoolean.parser') Handsteuerung   C:\Users\...    11

在另一种情况下，我编写了一个将结构变量设置为默认值的函数，但我更喜欢这种方法，因为它更短。

所有错误都是由“.parser = {"off", "on"}”引起的，但我没有弄错...

Answer 1

可以使用compound literals，所以把init改成

struct ChangeIntItem ChangeIntItemTypeBoolean = { .unit = "", .minimum = 0, .maximum = 1, .parser = (const char *[]){"off", "on"}};

测试

#include <stdio.h>
#include <stdint.h>

struct ChangeIntItem
{
    char *unit;
    const char **parser;
    int *changevalue;
    uint16_t *change_eeprom_value;
    int maximum;
    int minimum;
};

int main()
{
    struct ChangeIntItem ChangeIntItemTypeBoolean = { .unit = "", .minimum = 0, .maximum = 1, .parser = (const char *[]){"off", "on"}};

    printf ("%s - %s\n", ChangeIntItemTypeBoolean.parser[0], ChangeIntItemTypeBoolean.parser[1]);
}

输出

off - on

Answer 2

成员parser是一个指针。

改成指针数组，这样初始化可以保持不变：

 const char *parser[2];

或者使用复合文字或其他变量：

.parser = ( const char*[]){"off", "on"}

const char* array[2] = {"off", "on"};
.parser = array

结构初始化警告

Warning with struct initialization

c

struct

warnings

initialization