Essential c++，泛型编程风格读书笔记

#include
using namespace std;

/*数组作为函数参数传递的处理办法，数组长度或哨兵*/
template
type *find(type *arr,int size,const type & value)
{
	for(int i=0;i!=size;i++)
		if(arr[i]==value)
			return &arr[i];
	return 0;
}

template
type *find(type *arr,type * sentinel,const type & value)
{
	while(arr!=sentinel)
	{
		if(*arr==value)
			return arr;
		arr++;
	}
	return 0;
}

int main(){
	int arr[5]={1,2,3,4,5};
	int *result=find(arr,5,2);
	cout<<*result<

#include
#include
#include
#include
#include
using namespace std;

template
void print(const type1 & v,ostream_iterator &os)
{
	copy(v.begin(),v.end(),os);
	cout<
type  less_than_10(const type & v)
{
	type t;
	size_t i=0;
	while(i!=v.size())
	{
		if(v[i]<=10)
			t.push_back(v[i]);
		i++;
	}
	return t;
}

template
type filter(const type &v, typename type::value_type filter_value, bool (*pred)(typename type::value_type,typename type::value_type))/*函数指针*/
{
	type t;
	size_t i=0;
	while(i!=v.size())
	{
		if(pred(v[i],filter_value))
			t.push_back(v[i]);
		i++;
	}
	return t;
}

template
int count_occurs(const type &v,typename type::value_type val)
{
	typename type::const_iterator it=v.begin();/*注意迭代器类型*/
	int occurs=0;
	while((it=find(it,v.end(),val))!=v.end())
	{
		occurs++;
		it++;
	}
	return occurs;
}

template
bool less_than(type v1,type v2)
{
	return v1
type1 filter(const type1 & v,typename type1::value_type val,type2  functionobject)
{
	type1 t;
	typename type1::const_iterator it=v.begin();
	while(it!=v.end())
	{
		if(functionobject(*it,val))
			t.push_back(*it);
		it++;
	}
	return t;
}

/*绑定适配器*/
/*将函数对象的参数绑定到某特定值身上，使二元函数对象转化为一元函数对象*/
/*标准库提供了两个绑定适配器，
bind1st会将指定值绑定到第一个操作数
bind2nd会将指定值绑定到第二个操作数*/
template
type1 filter_1(const type1 & v,typename type1::value_type val,type2 function_object)
{
	type1 t;
	typename type1::const_iterator it=v.begin();
	while((it=find_if(it,v.end(),bind2nd(function_object,val)))!=v.end())
	{
		t.push_back(*it);
		it++;
	}
	return t;
}

/*传迭代器*/
template
OutputIterator filter_2(InputIterator first,InputIterator last,OutputIterator at,const Elemtype &val,Comp pred)
{
	while((first=find_if(first,last,bind2nd(pred,val)))!=last)
	{
		*at++=*first++;
	}
	return at;
}
int main(){
	int arr[]={2,5,3,7,11,13,4,7,16,9};
	const size_t arr_size=sizeof(arr)/sizeof(int);
	vector v(arr,arr+arr_size);
	ostream_iterator out(cout," ");
	print(v,out);

	vector t;
	t=filter(v,10,less());
	print(t,out);

	vector ivec(arr_size);
	filter_2(v.begin(),v.end(),ivec.begin(),10,less());
	print(ivec,out);
	
	t.clear();
	t=filter_1(v,10,less());
	print(t,out);


	sort(v.begin(),v.end(),less());/*调用标准函数对象*/
	print(v,out);

	sort(v.begin(),v.end(),greater());
	print(v,out);

	t.clear();
    t=less_than_10(v);
	print(t,out);

	t.clear();
	t=filter(v,10,less_than);/*函数指针*/

	cout<

#include
#include

/*迭代器适配器*/
#include
#include
#include
#include
#include
using namespace std;

int main(){
	ostream_iterator os(cout," ");
	int arr[5]={1,3,2,2,4};
	vector v(5);/*未指定大小，产生运行时错误*/
	copy(arr,arr+5,v.begin());
	copy(v.begin(),v.end(),os);
	cout< t;
	copy(arr,arr+5,back_inserter(t));/*使用迭代器适配器 back_inserter(),不用担心容器长度问题*/
	copy(t.begin(),t.end(),os);
	cout< t2;
	copy(arr,arr+5,inserter(t2,t2.end()));/*使用迭代器适配器inserter()，指定容器与插入位置*/
	copy(t2.begin(),t2.end(),os);
	cout< t3;/*vector容器不能在前端插入元素*/
	list t3;
	copy(arr,arr+5,front_inserter(t3));/*使用front_inserter迭代器适配器，在指定容器前端插入元素*/
	copy(t3.begin(),t3.end(),os);
	cout<

#include
#include
#include
#include
#include
using namespace std;

int main(){
	
	vector ivec;
	
	/*常规的输入方法*/
	//int data;
	/*while(cin>>data)
	{
		ivec.push_back(data);
	}*/

	istream_iterator is(cin);
	istream_iterator eof;
	copy(is,eof,back_inserter(ivec));

	sort(ivec.begin(),ivec.end(),greater());

	ostream_iterator os(cout," ");
	copy(ivec.begin(),ivec.end(),os);
	cout<

#include
#include
#include
#include
#include
#include
#include
using namespace std;

int main(){
	ifstream infile("1.txt");
	ofstream outfile("2.txt");

	if(!infile || !outfile)
	{
		cerr<<"文件打开失败！"< is(infile);
	istream_iterator eof;
	vector text;
	copy(is,eof,back_inserter(text));

	ostream_iterator os(outfile," ");
	sort(text.begin(),text.end());
	copy(text.begin(),text.end(),os);
	
	return 0;
}

#include
#include
#include
#include
#include
#include

#include
#include
#include
#include
#include
#include
using namespace std;

void readFile(vector &words,ifstream &infile)
{
	istream_iterator is(infile);
	istream_iterator eof;
	copy(is,eof,back_inserter(words));
}

class caseStringLength
{
public:
	bool operator()(const string &str1,const string &str2)
	{
		return str1.size() &words,ofstream &outfile)
{
	ostream_iterator os(outfile," ");
	copy(words.begin(),words.end(),os);
}
int main(){
	ifstream infile("3.txt");
	if(!infile)
	{
		cerr<<"文件打开失败！"< words;
	readFile(words,infile);
	sort(words.begin(),words.end(),caseStringLength());
	
	ofstream outfile("4.txt");
	writeFile(words,outfile);

	infile.close();
	outfile.close();
	return 0;
}

#include
#include
#include
#include
#include

#include
#include
#include
#include
#include
using namespace std;

void inputData(vector &data)
{
	istream_iterator is(cin);
	istream_iterator eof;
	copy(is,eof,back_inserter(data));
}

void doData(const vector &data, ofstream &infile1,ofstream &infile2)
{
	vector::const_iterator it=data.begin();
	ostream_iterator os1(infile1," ");
	ostream_iterator os2(infile2,"\n");

	vector v1;
	vector v2;
 	while(it!=data.end())
	{
		if(*it%2==0)
			v1.push_back(*it);
		else
			v2.push_back(*it);
		it++;
	}	
	copy(v1.begin(),v1.end(),os1);
	copy(v2.begin(),v2.end(),os2);
}


int main(){
	vector datas;
	inputData(datas);
	ofstream infile1("7.txt");
	ofstream infile2("8.txt");

	doData(datas,infile1,infile2);

	infile1.close();
	infile2.close();
	return 0;
}

#include
#include
#include
#include
using namespace std;

class even_elem{
public:
	bool operator()(int elem)
	{
		return (elem%2)?true:false;
	}
};

void Partition(vector datas)
{
	vector::iterator  division=partition(datas.begin(),datas.end(),even_elem());
	ostream_iterator os(cout," ");
	copy(datas.begin(),datas.end(),os);
	cout< datas)
{
	vector::iterator  division=stable_partition(datas.begin(),datas.end(),even_elem());
	ostream_iterator os(cout," ");
	copy(datas.begin(),datas.end(),os);
	cout< datas(arr,arr+sizeof(arr)/sizeof(int));
	Partition(datas);
	cout<<"*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-\n";
	Stable_partition(datas);
	return 0;
}

#include
#include
#include
#include
#include
using namespace std;

class even_elem{
public:
	bool operator()(int elem)
	{
		return (elem%2)?true:false;
	}
};

void Stable_partition(vector datas)
{
	ofstream odd_out("7.txt");
	ofstream even_out("8.txt");
	if(!odd_out || !even_out)
	{
		cerr<<"文件打开失败！"< os_odd(odd_out," ");
	ostream_iterator os_even(even_out,"\n");
	vector::iterator division=stable_partition(datas.begin(),datas.end(),even_elem());
	copy(datas.begin(),division,os_even);
	copy(division,datas.end(),os_odd);
}

int main(){
	int arr[]={29,23,20,22,17,15,26,51,19,12,35,40};
	vector datas(arr,arr+sizeof(arr)/sizeof(int));
	Stable_partition(datas);
	return 0;
}

#include
using namespace std;

class Matrix{
public:
	Matrix(int r,int c):_row(r),_col(c)
	{
		_pmat=new double[r*c];
		cout<<"构造函数"<

#include
using namespace std;

class val_class
{
public:
	val_class & val(const int & data ) 
	{
		cout<<"no-const:"<