Fixing std::swap(x, x) in base.

base/pickle.cc

Index: base/pickle.cc
diff --git a/base/pickle.cc b/base/pickle.cc
index 02f39b57b7bb8133ad23501f2eb619117af2c0de..487a8cdf52d514d4c07da856369ac61bf9c527e6 100644
--- a/base/pickle.cc
+++ b/base/pickle.cc
@@ -307,10 +307,6 @@ Pickle::~Pickle() {
 }
 
 Pickle& Pickle::operator=(const Pickle& other) {
-  if (this == &other) {
-    NOTREACHED();

[dcheng, 2017/04/05 20:22:18]

The post condition for CopyAssignment in N4618 [1] is:

t is equivalent to v, the value of v is unchanged

[1] http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/n4618.pdf

So I think we need to keep this self-assignment check for copy assignment.

[dyaroshev, 2017/04/05 20:42:47]

This NOTREACHED mislead me - I read it as move assignment.
Can I please drop it, it's super weird?

[dcheng, 2017/04/05 20:45:49]

Dropping the NOTREACHED() seems fine, as long as keep the early return or skip
the body.

[dyaroshev, 2017/04/05 20:54:17]

Done.

-    return *this;
-  }
   if (capacity_after_header_ == kCapacityReadOnly) {
     header_ = NULL;
     capacity_after_header_ = 0;