C ++模板化的流字符以十进制打印

Question

I am making a generic logger class which I prints anything passed into a file.

Logger::Instance()->write('c');
Logger::Instance()->write("this");
Logger::Instance()->write(5);

However I run into an issue where I have:

char c = 't';
Logger::Instance()->write(c);

Which prints decimal instead of the ascii:

116

Strings work fine but characters are the only thing having issues.

My code:

class Logger {
public:
    static Logger* Instance();
    bool open(string filename);
    template<typename T>
    void write(T data) {
        file << data;
    }
    bool close();

If I make a char specific printing function:

void write(char data) {
    file << data;

It will print the character. Not sure what is going on here.

Edit 1:

Just a summary.. So why does this print the numerical:

void write(T data) {
    file << data;
}

And this print the correct ascii:

void writeChar(char data) {
    file << data;
}

???

Edit 2:

Here is my code:

logger.h logger.cpp

Use this class and just go:

char c = 't';
Logger::Instance()->write(t);
Logger::Instance()->writeChar(t);

Edit 3:

Alright.. here is the last source file.

[keyboardhook.cpp][3]
[keyboardhook.h][4]
[main.cpp][5]

[3]: http://pastebin.com/VEav4kfn
[4]: http://pastebin.com/yPwF17yg
[5]: http://pastebin.com/JwHz2NBe

Take a look here:

if(isdigit(c)) {
        Logger::Instance()->write((char) c);
        Logger::Instance()->writeChar(c);
    } else if(isalpha(c)) {
        if(!shift)
            Logger::Instance()->writeChar(tolower((char) c));
        else
            Logger::Instance()->writeChar((char) c);

Stackoverflow keeps flagging my writing as 'code' and is giving me problems when saving.. sorry for the wait.

Answer 1

I tried the following and it worked fine in Visual C++ 2010 (as I would expect):

#include <iostream>

struct Logger {
    template <typename T>
    void write(T data) {
        std::cout << data;
    }
};

int main() {
    Logger *log = new Logger;
    char c = 't';
    log->write(c);
    delete log;
}

Perhaps you have some custom-defined operator<< 's that are causing this behavior for you? Could you post a sscce ?

Edit:

For future reference, here is what would have constituted a SSCCE for your problem (based on your complete code):

#include <iostream>

struct Logger {
template <typename T>
    void write(T data) {
        std::cout << data;
    }
};

int main() {
    Logger *log = new Logger;
    char c = 't';
    log->write(tolower(c));
    delete log;
}

The key problem is that the signature of tolower is int tolower(int c) , that is, it returns an integer, not a character. As such, write<int> is called, rather than write<char> .

Please keep in mind how important an sscce is! Your question didn't include the very important bit of code that caused the problem.