6.5.3 调试帮助

书中页数：P215
代码名称：wdebug.cc

#include <cstddef>
using std::size_t;

#include <cassert>
// assert is a preprocessor macro and therefore not in std
// hence we need to include cassert header, 
// but no using declaration for assert 

#include <string> 
using std::string;

#include <iostream> 
using std::endl; using std::cerr; using std::cin;

#include <cstddef>
using std::size_t;

void print(const int ia[], size_t size)
{
#ifndef NDEBUG
// __func__ is a local static defined by the compiler that holds the name of this function
cerr << __func__ << ": array size is " << size << endl;
#endif
// . . .
}

int main()
{
    string word = "foo";
    const string::size_type threshold = 5;
    if (word.size() < threshold) 
        cerr << "Error: " << __FILE__
             << " : in function " << __func__ 
             << " at line " << __LINE__ << endl
             << "       Compiled on " << __DATE__ 
             << " at " << __TIME__ << endl
             << "       Word read was \"" << word 
             << "\":  Length too short" << endl;
    word = "something longer than five chars";
    assert(word.size() > threshold);

    return 0;
}