C++ 编译器错误：未在此范围内声明 memset
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Compiler error: memset was not declared in this scope
提问by michael
I am trying to compile my C program in Ubuntu 9.10 (gcc 4.4.1).
我正在尝试在 Ubuntu 9.10 (gcc 4.4.1) 中编译我的 C 程序。
I am getting this error:
我收到此错误：
Rect.cpp:344: error: ‘memset' was not declared in this scope
But the problem is I have already included in my cpp file:
但问题是我已经包含在我的 cpp 文件中：
#include <stdio.h>
#include <stdlib.h>
And the same program compiles fine under Ubuntu 8.04 (gcc 4.2.4).
同样的程序在 Ubuntu 8.04 (gcc 4.2.4) 下编译得很好。
Please tell me what am I missing.
请告诉我我错过了什么。
回答by sth
You should include <string.h>(or its C++ equivalent, <cstring>).
您应该包括<string.h>（或其 C++ 等效项，<cstring>）。
回答by Paul R
Whevever you get a problem like this just go to the man page for the functionin question and it will tell you what header you are missing, e.g.
无论您遇到这样的问题，只需转到相关功能的手册页，它就会告诉您缺少什么标题，例如
$ man memset
MEMSET(3) BSD Library Functions Manual MEMSET(3)
NAME
memset -- fill a byte string with a byte value
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <string.h>
void *
memset(void *b, int c, size_t len);
Note that for C++ it's generally preferable to use the proper equivalent C++ headers, <cstring>/<cstdio>/<cstdlib>/etc, rather than C's <string.h>/<stdio.h>/<stdlib.h>/etc.
请注意，对于 C++，通常最好使用正确的等效 C++ 头文件<cstring>/ <cstdio>/ <cstdlib>/etc，而不是 C 的<string.h>/ <stdio.h>/ <stdlib.h>/etc。
