C语言 为什么 Clang 会警告：“||”内的“&&”？
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Why does Clang warn: `'&&' within '||'`?
提问by mxcl
My understanding is the parentheses make no difference, so is there any reason (other than to “improve“ code-clarity) that Clang warns this as a default? I prefer not to add the parentheses as I dislike adding code for code's sake.
我的理解是括号没有区别，那么 Clang 是否有任何理由（除了“提高”代码清晰度）将此作为默认警告？我不喜欢添加括号，因为我不喜欢为了代码而添加代码。
src/websocket.c:420:43: warning: '&&' within '||' [-Wlogical-op-parentheses]
if (rv == 0 && N != 0 || rv == -1 && errno == ECONNRESET) {
~~ ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
src/websocket.c:420:43: note: place parentheses around the '&&' expression to
silence this warning
if (rv == 0 && N != 0 || rv == -1 && errno == ECONNRESET) {
~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
采纳答案by Wooble
The natural tendency is to read it left to right, and it's easy to forget the operator precedence. That said, it's just a warning, and if you know what you're doing and your own style allows it, feel free to suppress it.
自然的趋势是从左到右阅读它，很容易忘记运算符的优先级。也就是说，这只是一个警告，如果您知道自己在做什么并且您自己的风格允许，请随意压制它。
回答by unwind
I'm guessing because it's simply a bit unclear, unless the reader is very good at C's operator precedence rules.
我猜测是因为它只是有点不清楚，除非读者非常擅长C 的运算符优先级规则。
Your expression is like this:
你的表情是这样的：
if (A && B || C && D)
and since &&has higher precendence than ||, it means
并且由于&&优先级高于||，这意味着
if ((A && B) || (C && D))
which I guess is what you mean, but it's not very clear when reading.
我想这就是你的意思，但阅读时不是很清楚。
