view: add make_view, ref-qualifiers, comparators

Makefile.am

@@ -268,6 +268,7 @@ UTIL_FILES   =			\
     vector.ipp			\
     version.cpp			\
     version.hpp			\
+    view.cpp			\
     view.ipp			\
     view.hpp
 
@@ -403,7 +404,8 @@ TEST_BIN = 			\
     test/tuple			\
     test/uri			\
     test/vector			\
-    test/version
+    test/version		\
+    test/view
 
 
 if PLATFORM_WIN32

test/view.cpp

@@ -0,0 +1,18 @@
+#include <cruft/util/tap.hpp>
+#include <cruft/util/view.hpp>
+    
+int
+main (int, char**)
+{
+    util::TAP::logger tap;
+
+    const std::string s = "this is a test string";
+    const std::string t = "not the same string";
+
+    tap.expect_eq (s, util::view<std::string::const_iterator> (s.cbegin (), s.cend ()), "string-const_iterator inequality comparison");
+    tap.expect_eq (s, util::view<const char*> (&*s.cbegin (), &*s.cend ()), "string-pointer equality comparison");
+
+    tap.expect_neq (t, util::make_view (s), "string-view inequality");
+
+    return tap.status ();
+}

view.cpp

@@ -0,0 +1,64 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Copyright 2016 Danny Robson <danny@nerdcruft.net>
+ */
+
+#include "./view.hpp"
+
+
+///////////////////////////////////////////////////////////////////////////////
+#define EQUALITY(A,B)                   \
+bool                                    \
+util::operator== (A a, B b)             \
+{                                       \
+    return a.size () == a.size () &&    \
+           std::equal (a.cbegin (),     \
+                       a.cend (),       \
+                       b.cbegin ());    \
+}
+
+
+EQUALITY(const std::string&, view<const char*>)
+EQUALITY(const std::string&, view<char*>)
+EQUALITY(const std::string&, view<std::string::const_iterator>)
+EQUALITY(const std::string&, view<std::string::iterator>)
+
+EQUALITY(view<const char*>,  const std::string&)
+EQUALITY(view<char*>,        const std::string&)
+EQUALITY(view<std::string::const_iterator>, const std::string&)
+EQUALITY(view<std::string::iterator>, const std::string&)
+
+#undef EQUALITY
+
+///////////////////////////////////////////////////////////////////////////////
+namespace util {
+#define OSTREAM(A)                                                          \
+    template <>                                                             \
+    std::ostream&                                                           \
+    operator<< (std::ostream &os, view<A> a) {                              \
+        std::copy (a.cbegin (),                                             \
+                   a.cend (),                                               \
+                   std::ostream_iterator<decltype(a)::value_type> (os));    \
+                                                                            \
+        return os;                                                          \
+    }
+
+    OSTREAM(const char*)
+    OSTREAM(char*)
+    OSTREAM(std::string::const_iterator)
+    OSTREAM(std::string::iterator)
+
+#undef OSTREAM
+}
+

view.hpp

@@ -11,7 +11,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  *
- * Copyright 2015 Danny Robson <danny@nerdcruft.net>
+ * Copyright 2015-2016 Danny Robson <danny@nerdcruft.net>
  */
 
 
@@ -30,14 +30,20 @@ namespace util {
         using value_type = typename std::iterator_traits<remove_restrict_t<T>>::value_type;
 
         template <size_t S>
-        constexpr view (const value_type (&arr)[S]) noexcept;
+        constexpr explicit
-        constexpr view (T first, T last) noexcept;
+        view (const value_type (&arr)[S]) noexcept;
 
-        constexpr T begin (void) const noexcept;
+        constexpr
-        constexpr T end   (void) const noexcept;
+        view (T first, T last) noexcept;
 
-        constexpr T cbegin (void) const noexcept;
+        constexpr T& begin (void) noexcept;
-        constexpr T cend   (void) const noexcept;
+        constexpr T& end   (void) noexcept;
+
+        constexpr const T& begin (void) const noexcept;
+        constexpr const T& end   (void) const noexcept;
+
+        constexpr const T& cbegin (void) const noexcept;
+        constexpr const T& cend   (void) const noexcept;
 
         constexpr T find (value_type) const noexcept;
 
@@ -54,6 +60,28 @@ namespace util {
         T m_end;
     };
 
+    template <typename T>
+    view<typename T::iterator>
+    make_view (T&);
+
+    template <typename T>
+    view<typename T::const_iterator>
+    make_view (const T&);
+
+    template <typename T>
+    auto
+    make_view (T&&) = delete;
+
+    bool operator== (const std::string&, view<const char*>);
+    bool operator== (const std::string&, view<char*>);
+    bool operator== (const std::string&, view<std::string::const_iterator>);
+    bool operator== (const std::string&, view<std::string::iterator>);
+
+    bool operator== (view<const char*>,  const std::string&);
+    bool operator== (view<char*>,        const std::string&);
+    bool operator== (view<std::string::const_iterator>, const std::string&);
+    bool operator== (view<std::string::iterator>, const std::string&);
+
     template <typename T>
     std::ostream&
     operator<< (std::ostream&, view<T>);

view.ipp

@@ -21,7 +21,8 @@
 #define __UTIL_VIEW_IPP
 
 
-#include "debug.hpp"
+#include "./debug.hpp"
+#include "./iterator.hpp"
 
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -45,7 +46,25 @@ util::view<T>::view (T _begin, T _end) noexcept:
 
 //-----------------------------------------------------------------------------
 template <typename T>
-constexpr T
+constexpr T&
+util::view<T>::begin (void) noexcept
+{
+    return m_begin;
+}
+
+
+//-----------------------------------------------------------------------------
+template <typename T>
+constexpr T&
+util::view<T>::end (void) noexcept
+{
+    return m_end;
+}
+
+
+//-----------------------------------------------------------------------------
+template <typename T>
+constexpr const T&
 util::view<T>::begin (void) const noexcept
 {
     return cbegin ();
@@ -54,7 +73,7 @@ util::view<T>::begin (void) const noexcept
 
 //-----------------------------------------------------------------------------
 template <typename T>
-constexpr T
+constexpr const T&
 util::view<T>::end (void) const noexcept
 {
     return cend ();
@@ -63,7 +82,7 @@ util::view<T>::end (void) const noexcept
 
 //-----------------------------------------------------------------------------
 template <typename T>
-constexpr T
+constexpr const T&
 util::view<T>::cbegin (void) const noexcept
 {
     return m_begin;
@@ -72,7 +91,7 @@ util::view<T>::cbegin (void) const noexcept
 
 //-----------------------------------------------------------------------------
 template <typename T>
-constexpr T
+constexpr const T&
 util::view<T>::cend (void) const noexcept
 {
     return m_end;   
@@ -133,14 +152,17 @@ util::view<T>::operator== (const view<T> rhs) const noexcept
 
 ///////////////////////////////////////////////////////////////////////////////
 template <typename T>
-std::ostream&
+util::view<typename T::iterator>
-util::operator<< (std::ostream &os, util::view<T> v)
+util::make_view (T &t)
 {
-    os << '[';
+    return util::view<typename T::iterator> { t.begin (), t.end () };
-
+}
-    for (auto &i: v)
+
-        os << v << ", ";
+
-
+//-----------------------------------------------------------------------------
-    os << ']';
+template <typename T>
-    return os;
+util::view<typename T::const_iterator>
+util::make_view (const T &t)
+{
+    return util::view<typename T::const_iterator> { t.cbegin (), t.cend () };
 }