Pensar en C++ (Volumen 1) - Grupo ARCO

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“Volumen1” — 2012/1/12 — 13:52 — page 511 — #549
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16.7. Introducción a los iteradores
iterator(PStash& pStash)
: ps(pStash), index(0) {}
// To create the end sentinel:
iterator(PStash& pStash, bool)
: ps(pStash), index(ps.next) {}
// Copy-constructor:
iterator(const iterator& rv)
: ps(rv.ps), index(rv.index) {}
iterator& operator=(const iterator& rv) {
ps = rv.ps;
index = rv.index;
return *this;
}
iterator& operator++() {
require(++index = 0,
"PStash::iterator::operator-- "
"moves index out of bounds");
return *this;
}
iterator& operator--(int) {
return operator--();
}
// Jump interator forward or backward:
iterator& operator+=(int amount) {
require(index + amount < ps.next &&
index + amount >= 0,
"PStash::iterator::operator+= "
"attempt to index out of bounds");
index += amount;
return *this;
}
iterator& operator-=(int amount) {
require(index - amount < ps.next &&
index - amount >= 0,
"PStash::iterator::operator-= "
"attempt to index out of bounds");
index -= amount;
return *this;
}
// Create a new iterator that’s moved forward
iterator operator+(int amount) const {
iterator ret(*this);
ret += amount; // op+= does bounds check
return ret;
}
T* current() const {
return ps.storage[index];
}
T* operator*() const { return current(); }
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