On Wed, May 20, 2015 at 11:32 AM, Venkateswara Rao Sanaka <moderncpp.venki@gmail.com> wrote:

Hi,

I am getting two empty strings from the following program,

void boost_split_test() {

    const string &text("-");

    vector<string> tokens;

    split(tokens, text, boost::is_any_of("-"), token_compress_on);

    cout << "size of tokens " << tokens.size() << '\n';

    for (auto const &e : tokens)

        cout << e.size() << '\n';

Output:

size of tokens 2
0
0

Is this expected output? I expecting an zero split parts. Could someone clarify?

This seems reasonable to me.

You asked it to split the string containing a single dash into parts separated by dashes.

The string gets split into an empty string, a dash (which is not returned to you, being the separator), and an empty string.

Consider splitting the input string "Foo-" (or "-Foo") compared to "Foo".

One gives two strings (one before the dash, one after the dash), the other gives one string (because there are no dashes).

Given a string with "n" separators, you should get "n+1" strings back (with the proviso that consecutive separators are collapsed together, so "Foo--" is treated the same as "Foo-").

-- Marshall

P.S. Checking the tests, I notice that there's no coverage for this case (separators at the beginning or the end of the input). I'll put it on my list. Thanks!