c++ - C++结构过多的初始化程序

Question

我试图在结构体中存储指针和数字数组，但这样做会导致too many initializers。

struct EmitArgs {
  const int numbers[];
  const void *src_struct;
};

void emit(const int numbers[], const void *src_struct) {
  EmitArgs emitArgs = {numbers, src_struct};
                            // ^^^^^^^^^^ too many initializers for 'EmitArgs'
}

我无法理解这个错误，因为它对我来说看起来是正确的。我究竟做错了什么？

Answer 1

最新的GCC可为您提供更多有用的诊断信息:

54192410.cpp:2:13: warning: ISO C++ forbids flexible array member ‘numbers’ [-Wpedantic]
    2 |   const int numbers[];
      |             ^~~~~~~
54192410.cpp:2:13: error: flexible array member ‘EmitArgs::numbers’ not at end of ‘struct EmitArgs’
54192410.cpp: In function ‘void emit(const int*, const void*)’:
54192410.cpp:7:43: error: non-static initialization of a flexible array member
    7 |   EmitArgs emitArgs = {numbers, src_struct};
      |                                           ^
54192410.cpp:7:43: warning: missing initializer for member ‘EmitArgs::src_struct’ [-Wmissing-field-initializers]
54192410.cpp:7:12: warning: unused variable ‘emitArgs’ [-Wunused-variable]
    7 |   EmitArgs emitArgs = {numbers, src_struct};
      |            ^~~~~~~~

假设我们有一个标准的C++数组:

struct EmitArgs {
  const int numbers[5];
  const void *src_struct;
};

然后我们仍然会遇到函数问题，因为数组作为函数参数传递时会衰减到指针。我们需要传递一个引用( void emit(const int (&numbers)[N], const void *s) )。