Merge pull request #7 from glenfe/develop

Move my ostream_string function to the IO library

doc/io.adoc

@@ -20,6 +20,7 @@ This library contains various utilities for the standard I/O library.
 include::ios_state.adoc[]
 include::quoted.adoc[]
 include::ostream_joiner.adoc[]
+include::ostream_put.adoc[]
 
 :leveloffset: -1
 

doc/ostream_put.adoc

@@ -0,0 +1,73 @@
+////
+Copyright 2019 Glen Joseph Fernandes
+(glenjofe@gmail.com)
+
+Distributed under the Boost Software License, Version 1.0.
+(http://www.boost.org/LICENSE_1_0.txt)
+////
+
+# Insert Formatted Output, <boost/io/ostream_put.hpp>
+:toc:
+:toc-title:
+:idprefix:
+
+## Description
+
+The header `<boost/io/ostream_put.hpp>` provides the function template
+`boost::io::ostream_put` for formatted output that satisfies the requirements
+of [ostream.formatted.reqmts].
+
+## Example
+
+The inserter for class template `basic_string_view` could be implemented as
+follows:
+
+```
+template<class charT, class traits>
+std::basic_ostream<charT, traits>&
+operator<<(std::basic_ostream<charT, traits>& os,
+    const basic_string_view<charT, traits>& str)
+{
+    return boost::io::ostream_put(os, str.data(), str.size());
+}
+```
+
+## Reference
+
+### Header Synopsis
+
+```
+namespace boost {
+namespace io {
+
+template<class charT, class traits>
+std::basic_ostream<charT, traits>&
+ostream_put(std::basic_ostream<charT, traits>& os,
+    const charT* data, std::size_t size);
+
+} // io
+} // boost
+```
+
+### Free functions
+
+```
+template<class charT, class traits>
+std::basic_ostream<charT, traits>&
+ostream_put(std::basic_ostream<charT, traits>& os,
+    const charT* data, std::size_t size);
+```
+
+[.specification]
+Effects:: Behaves like a formatted inserter (as described in
+[ostream.formatted.reqmts]) of `os`. Creates a character sequence `seq` of size
+characters starting at `data`, each widened using `os.widen()`
+([basic.ios.members]). Determines padding for `seq` as described in
+[ostream.formatted.reqmts]. Inserts `seq` into `os`. Calls `width(0)`.
+Returns:: `os`.
+
+## Acknowledgments
+
+Glen Fernandes updated the implementation of the `basic_string_ref` and
+`basic_string_view` stream insertion operators to write directly to the
+`basic_streambuf` and refactored that functionality into this common utility.

include/boost/io/ostream_put.hpp

@@ -0,0 +1,97 @@
+/*
+Copyright 2019 Glen Joseph Fernandes
+(glenjofe@gmail.com)
+
+Distributed under the Boost Software License, Version 1.0.
+(http://www.boost.org/LICENSE_1_0.txt)
+*/
+#ifndef BOOST_IO_OSTREAM_PUT_HPP
+#define BOOST_IO_OSTREAM_PUT_HPP
+
+#include <boost/config.hpp>
+#include <iosfwd>
+#include <cstddef>
+
+namespace boost {
+namespace io {
+namespace detail {
+
+template<class charT, class traits>
+inline std::size_t
+osp_put(std::basic_ostream<charT, traits>& os, const charT* data,
+    std::size_t size)
+{
+    return static_cast<std::size_t>(os.rdbuf()->sputn(data, size));
+}
+
+template<class charT, class traits>
+inline bool
+osp_fill(std::basic_ostream<charT, traits>& os, std::size_t size)
+{
+    charT c = os.fill();
+    charT fill[] = { c, c, c, c, c, c, c, c };
+    enum {
+        chunk = sizeof fill / sizeof(charT)
+    };
+    for (; size > chunk; size -= chunk) {
+        if (boost::io::detail::osp_put(os, fill, chunk) != chunk) {
+            return false;
+        }
+    }
+    return boost::io::detail::osp_put(os, fill, size) == size;
+}
+
+template<class charT, class traits>
+class osp_guard {
+public:
+    explicit osp_guard(std::basic_ostream<charT, traits>& os) BOOST_NOEXCEPT
+        : os_(&os) { }
+    ~osp_guard() BOOST_NOEXCEPT_IF(false) {
+        if (os_) {
+            os_->setstate(std::basic_ostream<charT, traits>::badbit);
+        }
+    }
+    void release() BOOST_NOEXCEPT {
+        os_ = 0;
+    }
+private:
+    osp_guard(const osp_guard&);
+    osp_guard& operator=(const osp_guard&);
+    std::basic_ostream<charT, traits>* os_;
+};
+
+} /* detail */
+
+template<class charT, class traits>
+inline std::basic_ostream<charT, traits>&
+ostream_put(std::basic_ostream<charT, traits>& os, const charT* data,
+    std::size_t size)
+{
+    typedef std::basic_ostream<charT, traits> stream;
+    detail::osp_guard<charT, traits> guard(os);
+    typename stream::sentry entry(os);
+    if (entry) {
+        std::size_t width = static_cast<std::size_t>(os.width());
+        if (width <= size) {
+            if (detail::osp_put(os, data, size) != size) {
+                return os;
+            }
+        } else if ((os.flags() & stream::adjustfield) == stream::left) {
+            if (detail::osp_put(os, data, size) != size ||
+                !detail::osp_fill(os, width - size)) {
+                return os;
+            }
+        } else if (!detail::osp_fill(os, width - size) ||
+            detail::osp_put(os, data, size) != size) {
+            return os;
+        }
+        os.width(0);
+    }
+    guard.release();
+    return os;
+}
+
+} /* io */
+} /* boost */
+
+#endif

test/Jamfile.v2

@@ -13,3 +13,4 @@ run ios_state_test.cpp ;
 run quoted_test.cpp ;
 run ostream_joiner_test.cpp ;
 run make_ostream_joiner_test.cpp ;
+run ostream_put_test.cpp ;

test/ostream_put_test.cpp

@@ -0,0 +1,136 @@
+/*
+Copyright 2019 Glen Joseph Fernandes
+(glenjofe@gmail.com)
+
+Distributed under the Boost Software License, Version 1.0.
+(http://www.boost.org/LICENSE_1_0.txt)
+*/
+#include <boost/core/lightweight_test.hpp>
+#include <boost/io/ostream_put.hpp>
+#include <sstream>
+#include <string>
+
+int main()
+{
+    {
+        std::ostringstream os;
+        os.width(1);
+        os.fill('.');
+        os.setf(std::ios_base::left, std::ios_base::adjustfield);
+        boost::io::ostream_put(os, "xy", 2);
+        BOOST_TEST(os.good());
+        BOOST_TEST(os.width() == 0);
+        BOOST_TEST(os.str() == "xy");
+    }
+    {
+        std::wostringstream os;
+        os.width(1);
+        os.fill('.');
+        os.setf(std::ios_base::left, std::ios_base::adjustfield);
+        boost::io::ostream_put(os, L"xy", 2);
+        BOOST_TEST(os.good());
+        BOOST_TEST(os.width() == 0);
+        BOOST_TEST(os.str() == L"xy");
+    }
+    {
+        std::ostringstream os;
+        os.width(1);
+        os.fill('.');
+        os.setf(std::ios_base::right, std::ios_base::adjustfield);
+        boost::io::ostream_put(os, "xy", 2);
+        BOOST_TEST(os.good());
+        BOOST_TEST(os.width() == 0);
+        BOOST_TEST(os.str() == "xy");
+    }
+    {
+        std::wostringstream os;
+        os.width(1);
+        os.fill('.');
+        os.setf(std::ios_base::right, std::ios_base::adjustfield);
+        boost::io::ostream_put(os, L"xy", 2);
+        BOOST_TEST(os.good());
+        BOOST_TEST(os.width() == 0);
+        BOOST_TEST(os.str() == L"xy");
+    }
+    {
+        std::ostringstream os;
+        os.width(4);
+        os.fill('.');
+        os.setf(std::ios_base::left, std::ios_base::adjustfield);
+        boost::io::ostream_put(os, "xy", 2);
+        BOOST_TEST(os.good());
+        BOOST_TEST(os.width() == 0);
+        BOOST_TEST(os.str() == "xy..");
+    }
+    {
+        std::wostringstream os;
+        os.width(4);
+        os.fill(L'.');
+        os.setf(std::ios_base::left, std::ios_base::adjustfield);
+        boost::io::ostream_put(os, L"xy", 2);
+        BOOST_TEST(os.good());
+        BOOST_TEST(os.width() == 0);
+        BOOST_TEST(os.str() == L"xy..");
+    }
+    {
+        std::ostringstream os;
+        os.width(4);
+        os.fill('.');
+        os.setf(std::ios_base::right, std::ios_base::adjustfield);
+        boost::io::ostream_put(os, "xy", 2);
+        BOOST_TEST(os.good());
+        BOOST_TEST(os.width() == 0);
+        BOOST_TEST(os.str() == "..xy");
+    }
+    {
+        std::wostringstream os;
+        os.width(4);
+        os.fill(L'.');
+        os.setf(std::ios_base::right, std::ios_base::adjustfield);
+        boost::io::ostream_put(os, L"xy", 2);
+        BOOST_TEST(os.good());
+        BOOST_TEST(os.width() == 0);
+        BOOST_TEST(os.str() == L"..xy");
+    }
+    {
+        std::ostringstream os;
+        os.width(12);
+        os.fill('.');
+        os.setf(std::ios_base::left, std::ios_base::adjustfield);
+        boost::io::ostream_put(os, "xy", 2);
+        BOOST_TEST(os.good());
+        BOOST_TEST(os.width() == 0);
+        BOOST_TEST(os.str() == "xy..........");
+    }
+    {
+        std::wostringstream os;
+        os.width(12);
+        os.fill(L'.');
+        os.setf(std::ios_base::left, std::ios_base::adjustfield);
+        boost::io::ostream_put(os, L"xy", 2);
+        BOOST_TEST(os.good());
+        BOOST_TEST(os.width() == 0);
+        BOOST_TEST(os.str() == L"xy..........");
+    }
+    {
+        std::ostringstream os;
+        os.width(12);
+        os.fill('.');
+        os.setf(std::ios_base::right, std::ios_base::adjustfield);
+        boost::io::ostream_put(os, "xy", 2);
+        BOOST_TEST(os.good());
+        BOOST_TEST(os.width() == 0);
+        BOOST_TEST(os.str() == "..........xy");
+    }
+    {
+        std::wostringstream os;
+        os.width(12);
+        os.fill(L'.');
+        os.setf(std::ios_base::right, std::ios_base::adjustfield);
+        boost::io::ostream_put(os, L"xy", 2);
+        BOOST_TEST(os.good());
+        BOOST_TEST(os.width() == 0);
+        BOOST_TEST(os.str() == L"..........xy");
+    }
+    return boost::report_errors();
+}