string_view-building-blocks

C++ string_view extension library.

Summary

This library provides basic functions for splitting and trimming a std::string_view which comes with C++17. It can also be used with older compilers (at least C++11) and a separate but standard conforming string_view implementation like boost::string_view.

Motivation

How to split a string in C++:

• How to split a string in C++
• The most elegant way to iterate the words of a string

How to split a string_view with svbb:

using svbb::make_view;
using svbb::string_view;
using svbb::tokenize;

const string_view view = make_view("cat,shark  ,dog, platypus ,cat");
const char delimeter = ',';
const string_view whitespace = make_view(" \t");

// svbb::tokenize creates a lazy input range
for(string_view token : tokenize(view, delimeter, whitespace)) {
    std::cout << "Substring: \"" << token << "\"\n";
}

Bonus: How to constexpr split a string_view with svbb:

using svbb::tokenize;
using namespace svbb::literals;

// svbb::_svc literal creates a string_view with constexpr char_traits
constexpr auto view = "cat,shark  ,dog, cat, platypus ,cat"_svc;
constexpr auto delimeter = ',';
constexpr auto whitespace = " \t"_svc;
constexpr auto token_range = tokenize(view, delimeter, whitespace);

static_assert(ctx::count(token_range, "cat"_svc) == 3);

Note:

• This compiles on Visual Studio 15.5 with "/std:c++latest".
• string_view is not meant as a compile time string, so this usage is only a by-product of putting constexpr everywhere.

Usage

• Make the contents of the include folder known to your target.
• #include "svbb/svbb.hpp"

For compatibility with older compilers you have to use a different string_view implementation like boost >= 1.61 . There is also a standalone version.

#include "boost/utility/string_view.hpp"
#define SVBB_STRING_VIEW_IMPL boost // let svbb know which string_view to use
#define SVBB_NO_CXX14_CONSTEXPR // if your compiler doesn't fully support C++14 constexpr
#define SVBB_NO_CONSTEXPR // if your compiler doesn't fully support C++11 constexpr
#define SVBB_NAMESPACE my_namespace // if you want another namespace than svbb
#include "svbb/svbb.hpp"