iosformat.h

#pragma once
 
#include <ostream>
#include <sstream>
#include <string>
 
namespace beast {
 
// A collection of handy stream manipulators and
// functions to produce nice looking log output.
 
struct leftw
{
    explicit leftw(int width_) : width(width_)
    {
    }
    int const width;
    template <class CharT, class Traits>
    friend std::basic_ios<CharT, Traits>&
    operator<<(std::basic_ios<CharT, Traits>& ios, leftw const& p)
    {
        ios.setf(std::ios_base::left, std::ios_base::adjustfield);
        ios.width(p.width);
        return ios;
    }
};
 
template <class CharT, class Traits, class Allocator>
std::basic_string<CharT, Traits, Allocator>
heading(std::basic_string<CharT, Traits, Allocator> title, int width = 80, CharT fill = CharT('-'))
{
    title.reserve(width);
    title.push_back(CharT(' '));
    title.resize(width, fill);
    return title;
}
 
struct divider
{
    using CharT = char;
    explicit divider(int width_ = 80, CharT fill_ = CharT('-')) : width(width_), fill(fill_)
    {
    }
    int const width;
    CharT const fill;
    template <class CharT, class Traits>
    friend std::basic_ostream<CharT, Traits>&
    operator<<(std::basic_ostream<CharT, Traits>& os, divider const& d)
    {
        os << std::basic_string<CharT, Traits>(d.width, d.fill);
        return os;
    }
};
 
struct fpad
{
    explicit fpad(int width_, int pad_ = 0, char fill_ = ' ') : width(width_ + pad_), fill(fill_)
    {
    }
    int const width;
    char const fill;
    template <class CharT, class Traits>
    friend std::basic_ostream<CharT, Traits>&
    operator<<(std::basic_ostream<CharT, Traits>& os, fpad const& f)
    {
        os << std::basic_string<CharT, Traits>(f.width, f.fill);
        return os;
    }
};
 
//------------------------------------------------------------------------------
 
namespace detail {
 
template <typename T>
std::string
to_string(T const& t)
{
    std::stringstream ss;
    ss << t;
    return ss.str();
}
 
}  // namespace detail
 
template <
    class CharT,
    class Traits = std::char_traits<CharT>,
    class Allocator = std::allocator<CharT>>
class field_t
{
public:
    using string_t = std::basic_string<CharT, Traits, Allocator>;
    field_t(string_t const& text_, int width_, int pad_, bool right_)
        : text(text_), width(width_), pad(pad_), right(right_)
    {
    }
    string_t const text;
    int const width;
    int const pad;
    bool const right;
    template <class CharT2, class Traits2>
    friend std::basic_ostream<CharT2, Traits2>&
    operator<<(std::basic_ostream<CharT2, Traits2>& os, field_t<CharT, Traits, Allocator> const& f)
    {
        std::size_t const length(f.text.length());
        if (f.right)
        {
            if (length < f.width)
                os << std::basic_string<CharT2, Traits2>(f.width - length, CharT2(' '));
            os << f.text;
        }
        else
        {
            os << f.text;
            if (length < f.width)
                os << std::basic_string<CharT2, Traits2>(f.width - length, CharT2(' '));
        }
        if (f.pad != 0)
            os << string_t(f.pad, CharT(' '));
        return os;
    }
};
 
template <class CharT, class Traits, class Allocator>
field_t<CharT, Traits, Allocator>
field(
    std::basic_string<CharT, Traits, Allocator> const& text,
    int width = 8,
    int pad = 0,
    bool right = false)
{
    return field_t<CharT, Traits, Allocator>(text, width, pad, right);
}
 
template <class CharT>
field_t<CharT>
field(CharT const* text, int width = 8, int pad = 0, bool right = false)
{
    return field_t<CharT, std::char_traits<CharT>, std::allocator<CharT>>(
        std::basic_string<CharT, std::char_traits<CharT>, std::allocator<CharT>>(text),
        width,
        pad,
        right);
}
 
template <typename T>
field_t<char>
field(T const& t, int width = 8, int pad = 0, bool right = false)
{
    std::string const text(detail::to_string(t));
    return field(text, width, pad, right);
}
 
template <class CharT, class Traits, class Allocator>
field_t<CharT, Traits, Allocator>
rField(std::basic_string<CharT, Traits, Allocator> const& text, int width = 8, int pad = 0)
{
    return field_t<CharT, Traits, Allocator>(text, width, pad, true);
}
 
template <class CharT>
field_t<CharT>
rField(CharT const* text, int width = 8, int pad = 0)
{
    return field_t<CharT, std::char_traits<CharT>, std::allocator<CharT>>(
        std::basic_string<CharT, std::char_traits<CharT>, std::allocator<CharT>>(text),
        width,
        pad,
        true);
}
 
template <typename T>
field_t<char>
rField(T const& t, int width = 8, int pad = 0)
{
    std::string const text(detail::to_string(t));
    return field(text, width, pad, true);
}
}  // namespace beast