【求助】关于pthread_mutex_t变量的初始化问题

[god_fish]

#include <pthread.h>
#include <stdio.h>

class A
{
public:
A();
pthread_mutex_t m;
};

A::A():m (PTHREAD_MUTEX_INITIALIZER)
{
}

int main()
{
return 0;
}

编译出现错误：
testA.cpp: In constructor `A::A()':
testA.cpp:14: parse error before `{' token
testA.cpp:14: parse error before `{' token

请问这是什么原因？应该如何初始化呢？

[pottichu]

//lock.h 头文件
#ifndef AUTO_LOCK_H
#define AUTO_LOCK_H

#include <pthread.h>

namespace util
{

class  LockableObject {
public:
	LockableObject(){};
	virtual ~LockableObject(){};

	virtual void lock() = 0;
	virtual void unlock() = 0;
};

class  ThreadMutex : public LockableObject {
public:
	ThreadMutex();
	virtual ~ThreadMutex();
	virtual void lock();
	virtual void unlock();

private:
	pthread_mutex_t m_cs;
};

class  AutoLock {
public:

	AutoLock(LockableObject* pLockable);
	~AutoLock();

private:
	LockableObject* m_pLockable;
};

}
#endif
 

 #include "lock.h"
#include <stdio.h>
//lock.cpp 头文件
namespace util
{

ThreadMutex::ThreadMutex() {
	pthread_mutex_init(&m_cs, NULL);
}

ThreadMutex::~ThreadMutex() {
	pthread_mutex_destroy(&m_cs);
}

void ThreadMutex::lock() {
	pthread_mutex_lock(&m_cs);
}

void ThreadMutex::unlock() {
	pthread_mutex_unlock(&m_cs);
}

AutoLock::AutoLock(LockableObject* pLockable) {
	m_pLockable = pLockable;
	m_pLockable->lock();
}

AutoLock::~AutoLock() {
	m_pLockable->unlock();
}

}

//main.cpp
#include <stdio.h>
#include "lock.h"
using namespace util;

int main(int argc, char *argv[])
{
	 ThreadMutex cs;
	 AutoLock(cs);
	
	return 0;
}

[pottichu]

#include   <pthread.h> 
#include   <stdio.h> 

class   A 
{ 
public:                 
	A(); 
private:
	pthread_mutex_t     m; 
}; 

A::A() 
{ 
	pthread_mutex_init(&m, NULL);
} 

int   main() 
{ 
	return   0; 
}