小编del*_*amp的帖子

我想知道android push框架如何能够区分通过GCM收到的数据并将其转发到适合它的应用程序？

谁能让我知道它是如何完成的？

我在C++中尝试了一个示例泛型函数,代码如下:

#include <iostream>
#include <string>
#include <algorithm>

using namespace std;

template <typename T>
T max(T a, T b){
    return (a>b)?a:b;
}

int main()
{
    int a=2,b=4;
    float af = 2.01,bf=2.012;
    double ad = 2.11,bd=1.22;
    cout<<max(a,b);
}

我收到的错误是

main.cpp: In function ‘int main()’:
main.cpp:20:18: error: call of overloaded ‘max(int&, int&)’ is ambiguous
     cout<<max(a,b);
                  ^
main.cpp:20:18: note: candidates are:
main.cpp:9:3: note: T max(T, T) [with T = int]
 T max(T a, T b){
   ^main.cpp: In function ‘int main()’:
main.cpp:20:18: error: call of …

我收到了一个错误

10:13: error: no match for 'operator^' (operand types are 'std::basic_ostream<char>' and 'int')
10:13: note: candidates are:
In file included from /usr/include/c++/4.9/ios:42:0,
             from /usr/include/c++/4.9/ostream:38,
             from /usr/include/c++/4.9/iostream:39,
             from 2:
/usr/include/c++/4.9/bits/ios_base.h:161:3: note: std::_Ios_Iostate std::operator^(std::_Ios_Iostate, std::_Ios_Iostate)
operator^(_Ios_Iostate __a, _Ios_Iostate __b)
^

代码是

// Example program
#include <iostream>
#include <string>

int main()
{
int a=1;
int b=2;

std::cout<<a^b;
}

有哪些操作数可以使用operator ^？

考虑以下功能

1. 额外费用4运营
2. 分配成本1运营
3. 比较成本1运营

计算上述功能将花费14次操作

int function1(int a,int b,int c, int d, int e)
{
int returnNumber;
//int no = randomNumber(); //Some Random Number Generator Function , Lets Assume the cost of this function to be 0 for simplicity purpose

switch(randomNumber())
   {
   case 0: returnNumber = a+b;  // costs 6 Operations , Case Check costs 1, assignment costs 1 and addition costs 4
           break;
   case 1: returnNumber = c+d;  // Costs 6 Operations 
           break;
   default: returnNumber = e;   // costs …