Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
1.4k views
in Technique[技术] by (71.8m points)

new operator - How do you 'realloc' in C++?

How can I realloc in C++? It seems to be missing from the language - there is new and delete but not resize!

I need it because as my program reads more data, I need to reallocate the buffer to hold it. I don't think deleteing the old pointer and newing a new, bigger one, is the right option.

Question&Answers:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

Use ::std::vector!

Type* t = (Type*)malloc(sizeof(Type)*n) 
memset(t, 0, sizeof(Type)*m)

becomes

::std::vector<Type> t(n, 0);

Then

t = (Type*)realloc(t, sizeof(Type) * n2);

becomes

t.resize(n2);

If you want to pass pointer into function, instead of

Foo(t)

use

Foo(&t[0])

It is absolutely correct C++ code, because vector is a smart C-array.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...