k*******3
发帖数: 1909 | 1 essential C++ 中文版4.6节“打造一个iterator class”中分别定义了++的前置和后
置版
本，请问为啥一个返回Triangular_iterator&，而一个返回Triangular_iterator类呢？
谢谢。
inline Triangular_iterator& Triangular_iterator::
operator++()
{ // prefix instance
++_index;
check_integrity();
return *this;
}
inline Triangular_iterator Triangular_iterator::
operator++( int )
{ // postfix instance
Triangular_iterator tmp = *this;
++_index;
check_integrity();
return tmp;
} |
x****u
发帖数: 44466 | 2 引用就是指针
呢？
【在 k*******3 的大作中提到】
: essential C++ 中文版4.6节“打造一个iterator class”中分别定义了++的前置和后
: 置版
: 本，请问为啥一个返回Triangular_iterator&，而一个返回Triangular_iterator类呢？
: 谢谢。
: inline Triangular_iterator& Triangular_iterator::
: operator++()
: { // prefix instance
: ++_index;
: check_integrity();
: return *this;
|
k*******3
发帖数: 1909 | 3 为啥前置++和后置++一个返回值一个返回引用呢？
【在 x****u 的大作中提到】
: 引用就是指针
:
: 呢？
|
f*******n
发帖数: 12623 | 4 operator++() is for pre-increment (++x)
operator++(int) is for post-increment (x++)
Because both pre and post are unary operators, there is no way to tell them
apart, so C++ made a special case, and post-increment / post-decrement take
an additional int parameter.
Pre-increment returns a reference, because a pre-increment expression is an
lvalue (you can assign to it or take the address of it, etc.). Post-
increment returns a copy, because a post-increment expression is a rvalue.
呢？
【在 k*******3 的大作中提到】
: essential C++ 中文版4.6节“打造一个iterator class”中分别定义了++的前置和后
: 置版
: 本，请问为啥一个返回Triangular_iterator&，而一个返回Triangular_iterator类呢？
: 谢谢。
: inline Triangular_iterator& Triangular_iterator::
: operator++()
: { // prefix instance
: ++_index;
: check_integrity();
: return *this;
|
k*******3
发帖数: 1909 | 5 高！ 学习了。谢谢
them
take
an
【在 f*******n 的大作中提到】
: operator++() is for pre-increment (++x)
: operator++(int) is for post-increment (x++)
: Because both pre and post are unary operators, there is no way to tell them
: apart, so C++ made a special case, and post-increment / post-decrement take
: an additional int parameter.
: Pre-increment returns a reference, because a pre-increment expression is an
: lvalue (you can assign to it or take the address of it, etc.). Post-
: increment returns a copy, because a post-increment expression is a rvalue.
:
: 呢？
|
