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我不时遇到“衰减”一词，例如当作为函数参数传入的数组衰减为指针时，或者当函数衰减为函数指针时。如果我正在编写 ac 编译器，我在哪里可以找到正式定义的“衰减”一词，以及它发生的所有情况都将在哪里记录？

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标准中的官方术语是“左值转换”。在当前版本的标准 (C11) 中，您可以在 6.3.2.1 p3 中找到它。

于 2012-05-02T16:14:40.040 回答
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第二次谷歌搜索结果如下：

The K&R method of reducing arrays to pointers
 ---------------------------------------------
 K&R tried to create a unified treatment of arrays and pointers, one that 
 would expose rather than hide the array equation in the compiler's code. 
 They found an elegant solution, albeit a bit complicated. The "ugly" 
 array equation is replaced in their formulation by four rules:

    1) An array of dimension N is a 1D array with
       elements that are arrays of dimension N-1.

    2) Pointer addition is defined by:

          ptr # n = ptr + n * size(type-pointed-into)

       "#" denotes here pointer addition to avoid 
       confusion with ordinary addition.
       The function "size()" returns object's sizes.

    3) The famous "decay convention": an array is 
       treated as a pointer that points to the 
       first element of the array.

       The decay convention shouldn't be applied
       more than once to the same object.

    4) Taking a subscript with value i is equivalent 
       to the operation: "pointer-add i and then 
       type-dereference the sum", i.e.

          xxx[i] = *(xxx # i)


        When rule #4 + rule #3 are applied recursively 
        (this is the case of a multi-dimensional array), 
        only the data type is dereferenced and not the 
        pointer's value, except on the last step.

资源

于 2012-05-02T15:35:02.383 回答
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数组名称衰减意味着它的值被视为（=具有类型和值）作为指向其第一个元素的指针。请注意，数组名称并不总是衰减（例如，不作为 sizeof 运算符的操作数）。不完美的同义词可能被视为或重写为或简单地用作。

于 2012-05-02T16:00:59.237 回答
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C 标准是回答此类问题的唯一方法。

如果你想购买官方文件，那么你需要寻找ISO/IEC 9899:2011。或者可能更喜欢 1999 年或 1989 年的旧标准。

或者，2011 标准的最终草案可在此处获得，并且应该足够接近： http ://www.open-std.org/jtc1/sc22/wg14/www/docs/n1570.pdf

于 2012-05-02T15:44:24.523 回答