Question

I need to search an array of c-strings for a substring.

I created what I thought would return me the answer but it is only syntactically correct but semantically wrong, but I’m not sure where I have gone wrong.

There is also a sub-question to this. Which I will ask after showing you the example I tried.

#include <boost/algorithm/string/find.hpp>

const char Months[12][20] = {"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"};

void Test()
{
    typedef boost::iterator_range<boost::range_iterator<const char [20]>::type > constCharRange;
    boost::iterator_range<char const *> ir = find_first("January", months);
}

ir.first == ir.last

The results of the iterator show that I have not written this correctly.

I’m not sure whether the fact that the first parameter is actually const char [8] is having a detrimental effect.

My main question what should I do to correct it, and the supplemental question is how can I extract the type that find_first requires from constCharRange or indeed any such typedef.

Edit:

I see that I have used end incorrectly. I’ve then managed to get slightly different example to work however they are not compatible with the definitions I actually have to use (I can add to the code but not change the existing definition).

const std::string Months[]= { /*same data as before*/
void StringTest2()
{
    const std::string* sptr =0;
    sptr = std::find(boost::begin(Months), boost::end(Months), std::string("February"));
    if (sptr)
    {
        string sResult(*sptr);
    }
}

Another Test

const char* Months[]= { /*same data as before*/
void StringTest3()
{
    const char **sptr = std::find(boost::begin(Months), boost::end(Months), "February");
    if (sptr)
    {
        string sResult(*sptr);
    }
}

Here is the nearest I can get, but I can’t seem to get the return type spec correct

void StringTest4()
{
    const char Months[12][20]Months[]= { /*same data as before*/
    std::find(boost::begin(Months), boost::end(Months), "February");
}

Answer 1

I can correct StringTest4 to do exact matches, however this solution won’t work for partial ones.

void StringTest4()
{
    boost::range_iterator<const char [12][20]>::type sptr = std::find(boost::begin(Months), boost::end(Months), std::string("February"));
    if (sptr)
    {
        string sResult(*sptr);
    }
}

Note the passing of std::string rather than just "February" if we don’t do this then std::find will just be doing a pointer comparison which would therefore result in failure.

I would still prefer to use this with string_algo, but I’m still not sure which bits I would need for it to successfully work with const char Months[12][20]