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
1.1k views
in Technique[技术] by (71.8m points)

new operator - C++ Object without new

this is a really simple question but I havn't done c++ properly for years and so I'm a little baffled by this. Also, it's not the easiest thing (for me at least) to look up on the internet, not for trying.

Why doesn't this use the new keyword and how does it work?

Basically, what's going on here?

CPlayer newPlayer = CPlayer(position, attacker);
See Question&Answers more detail: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)

This expression:

CPlayer(position, attacker)

creates a temporary object of type CPlayer using the above constructor, then:

CPlayer newPlayer =...;

The mentioned temporary object gets copied using the copy constructor to newPlayer. A better way is to write the following to avoid temporaries:

CPlayer newPlayer(position, attacker);

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

...