int 和 C.int 有什么区别？

Question

import "C"

func f() {
  var vGo int
  var vC  C.int
  // fails to compile with error
  // cannot use &vGo (type *int) as type *C.int in argument to...
  C.c_function(&vGo)  
  // compiles just fine:
  C.c_function(&vC)
}

我用CGO_ENABLED=1 GOARCH=arm编译...

在这种情况下，int 和 C.int 类型有什么不同？
我在哪里可以找到有关 GO 中 C 类型的更多信息？

Answer 1

类型之间有什么区别？这取决于。如果您使用的是 64 位，则 Go int 将为 64 位，而 C int 将为 32 位。如果您使用的是 32 位，则没有真正的区别。

我在哪里可以找到有关 Go 中 C 类型的更多信息？查看 C 的文档。如评论中所述，Go 中不允许隐式数字类型转换，因此需要进行转换。

Answer 2

Go 故意不支持隐式类型转换，但有一些例外1:

A value x is assignable to a variable of type T ("x is assignable to T") in any of these cases:

x's type is identical to T.

x's type V and T have identical underlying types and at least one of V or T is not a named type.

T is an interface type and x implements T.

x is a bidirectional channel value, T is a channel type, x's type V and T have identical element types, and at least one of V or T is not a named type.

x is the predeclared identifier nil and T is a pointer, function, slice, map, channel, or interface type.

x is an untyped constant representable by a value of type T.

您需要进行转换以匹配可能不同的内存布局2。

int 和 C.int 有什么区别？

What's the difference between int and C.int in go?

go

cgo