Implement << operator for std basic_ostream and etl string_view (#1040)

* Implement << operator for std basic_ostream and etl string_view

* Implement << operator for std basic_ostream and etl ibasic_string.  Still working through tests

* Should be all tests

* Fix comment

include/etl/basic_string.h

@@ -54,6 +54,10 @@ SOFTWARE.
   #include <string_view>
 #endif
 
+#if ETL_USING_STL
+  #include <ostream>
+#endif
+
 #include "private/minmax_push.h"
 
 //*****************************************************************************
@@ -2962,6 +2966,23 @@ namespace etl
   {
     return !(lhs < rhs);
   }
+
+  //***************************************************************************
+  /// Operator overload to write to std basic_ostream
+  ///\param os Reference to the output stream.
+  ///\param str Reference to the string to write.
+  ///\return Reference to the output stream, for chaining write operations.
+  ///\ingroup string
+  //***************************************************************************
+#if ETL_USING_STL
+  template <typename T>
+  std::basic_ostream<T, std::char_traits<T> > &operator<<(std::basic_ostream<T, std::char_traits<T> > &os, 
+                                                          const etl::ibasic_string<T>& str)
+  {
+    os.write(str.data(), str.size());
+    return os;
+  }
+#endif
 }
 
 #include "private/minmax_pop.h"

include/etl/string_view.h

@@ -47,6 +47,10 @@ SOFTWARE.
   #include <string_view>
 #endif
 
+#if ETL_USING_STL
+  #include <ostream>
+#endif
+
 #include <stdint.h>
 
 namespace etl
@@ -972,6 +976,19 @@ void swap(etl::basic_string_view<T, etl::char_traits<T> >& lhs, etl::basic_strin
   lhs.swap(rhs);
 }
 
+//*************************************************************************
+/// Operator overload to write to std basic_ostream
+//*************************************************************************
+#if ETL_USING_STL
+template <typename T>
+std::basic_ostream<T, std::char_traits<T> > &operator<<(std::basic_ostream<T, std::char_traits<T> > &os, 
+                                                        etl::basic_string_view<T, etl::char_traits<T> > text)
+{
+  os.write(text.data(), text.size());
+  return os;
+}
+#endif
+
 #include "private/minmax_pop.h"
 
 #endif

test/test_string_char.cpp

@@ -5310,5 +5310,23 @@ namespace
 #endif
       CHECK_EQUAL(text.max_size(), text.size());
     }
+
+    //*************************************************************************
+#if ETL_USING_STL
+    TEST_FIXTURE(SetupFixture, test_write_string_to_std_basic_ostream)
+    {
+      Text text1 = STR("Hello World");
+
+      std::stringstream sstream;
+
+      sstream << text1;
+
+      TextSTD sstream_string = sstream.str();
+
+      View sstream_view(sstream_string.data(), sstream_string.size());
+
+      CHECK(text1 == sstream_view);
+    }
+#endif
   };
 }

test/test_string_char_external_buffer.cpp

@@ -5689,5 +5689,24 @@ namespace
 #endif
       CHECK_EQUAL(text.max_size(), text.size());
     }
+
+    //*************************************************************************
+#if ETL_USING_STL
+    TEST_FIXTURE(SetupFixture, test_write_string_to_std_basic_ostream)
+    {
+      TextBuffer buffer1{0};
+      Text text1(STR("Hello World"), buffer1.data(), buffer1.size());
+
+      std::stringstream sstream;
+
+      sstream << text1;
+
+      TextSTD sstream_string = sstream.str();
+
+      View sstream_view(sstream_string.data(), sstream_string.size());
+
+      CHECK(text1 == sstream_view);
+    }
+#endif
   };
 }

test/test_string_u16.cpp

@@ -5324,5 +5324,23 @@ namespace
 #endif
       CHECK_EQUAL(text.max_size(), text.size());
     }
+
+    //*************************************************************************
+#if ETL_USING_STL
+    TEST_FIXTURE(SetupFixture, test_write_string_to_std_basic_ostream)
+    {
+      Text text1 = STR("Hello World");
+
+      std::basic_stringstream<char16_t> sstream;
+
+      sstream << text1;
+
+      TextSTD sstream_string = sstream.str();
+
+      View sstream_view(sstream_string.data(), sstream_string.size());
+
+      CHECK(text1 == sstream_view);
+    }
+#endif
   };
 }

test/test_string_u16_external_buffer.cpp

@@ -5677,5 +5677,24 @@ namespace
 #endif
       CHECK_EQUAL(text.max_size(), text.size());
     }
+
+    //*************************************************************************
+#if ETL_USING_STL
+    TEST_FIXTURE(SetupFixture, test_write_string_to_std_basic_ostream)
+    {
+      TextBuffer buffer1{0};
+      Text text1(STR("Hello World"), buffer1.data(), buffer1.size());
+
+      std::basic_stringstream<char16_t> sstream;
+
+      sstream << text1;
+
+      TextSTD sstream_string = sstream.str();
+
+      View sstream_view(sstream_string.data(), sstream_string.size());
+
+      CHECK(text1 == sstream_view);
+    }
+#endif
   };
 }

test/test_string_u32.cpp

@@ -5324,5 +5324,23 @@ namespace
 #endif
       CHECK_EQUAL(text.max_size(), text.size());
     }
+
+    //*************************************************************************
+#if ETL_USING_STL
+    TEST_FIXTURE(SetupFixture, test_write_string_to_std_basic_ostream)
+    {
+      Text text1 = STR("Hello World");
+
+      std::basic_stringstream<char32_t> sstream;
+
+      sstream << text1;
+
+      TextSTD sstream_string = sstream.str();
+
+      View sstream_view(sstream_string.data(), sstream_string.size());
+
+      CHECK(text1 == sstream_view);
+    }
+#endif
   };
 }

test/test_string_u32_external_buffer.cpp

@@ -5677,5 +5677,24 @@ namespace
 #endif
       CHECK_EQUAL(text.max_size(), text.size());
     }
+
+    //*************************************************************************
+#if ETL_USING_STL
+    TEST_FIXTURE(SetupFixture, test_write_string_to_std_basic_ostream)
+    {
+      TextBuffer buffer1{0};
+      Text text1(STR("Hello World"), buffer1.data(), buffer1.size());
+
+      std::basic_stringstream<char32_t> sstream;
+
+      sstream << text1;
+
+      TextSTD sstream_string = sstream.str();
+
+      View sstream_view(sstream_string.data(), sstream_string.size());
+
+      CHECK(text1 == sstream_view);
+    }
+#endif
   };
 }

test/test_string_u8.cpp

@@ -5327,6 +5327,24 @@ namespace
 #endif
       CHECK_EQUAL(text.max_size(), text.size());
     }
+
+    //*************************************************************************
+#if ETL_USING_STL
+    TEST_FIXTURE(SetupFixture, test_write_string_to_std_basic_ostream)
+    {
+      Text text1 = STR("Hello World");
+
+      std::basic_stringstream<char8_t> sstream;
+
+      sstream << text1;
+
+      TextSTD sstream_string = sstream.str();
+
+      View sstream_view(sstream_string.data(), sstream_string.size());
+
+      CHECK(text1 == sstream_view);
+    }
+#endif
   };
 }
 

test/test_string_u8_external_buffer.cpp

@@ -5706,6 +5706,25 @@ namespace
 #endif
       CHECK_EQUAL(text.max_size(), text.size());
     }
+
+    //*************************************************************************
+#if ETL_USING_STL
+    TEST_FIXTURE(SetupFixture, test_write_string_to_std_basic_ostream)
+    {
+      TextBuffer buffer1{0};
+      Text text1(STR("Hello World"), buffer1.data(), buffer1.size());
+
+      std::basic_stringstream<char8_t> sstream;
+
+      sstream << text1;
+
+      TextSTD sstream_string = sstream.str();
+
+      View sstream_view(sstream_string.data(), sstream_string.size());
+
+      CHECK(text1 == sstream_view);
+    }
+#endif
   };
 }
 

test/test_string_view.cpp

@@ -1120,5 +1120,40 @@ namespace
       CHECK_TRUE((u16view == U16View{ u"Hello World", etl::strlen(u"Hello World") }));
       CHECK_TRUE((u32view == U32View{ U"Hello World", etl::strlen(U"Hello World") }));
     }
+
+    //*************************************************************************
+#if ETL_USING_STL
+    TEST(write_to_std_stream)
+    {
+      View view{ "Hello World" };
+      WView wview{ L"Hello World" };
+      U16View u16view{ u"Hello World" };
+      U32View u32view{ U"Hello World" };
+
+      std::stringstream sstream;
+      std::wstringstream wsstream;
+      std::basic_stringstream<char16_t> u16sstream;
+      std::basic_stringstream<char32_t> u32sstream;
+
+      sstream << view;
+      std::string sstream_string = sstream.str();
+      wsstream << wview;
+      std::wstring wsstream_string = wsstream.str();
+      u16sstream << u16view;
+      std::u16string u16sstream_string = u16sstream.str();
+      u32sstream << u32view;
+      std::u32string u32sstream_string = u32sstream.str();
+
+      View sstream_view(sstream_string.data(), sstream_string.size());
+      WView wsstream_view(wsstream_string.data(), wsstream_string.size());
+      U16View u16sstream_view(u16sstream_string.data(), u16sstream_string.size());
+      U32View u32sstream_view(u32sstream_string.data(), u32sstream_string.size());
+
+      CHECK_TRUE(view == sstream_view);
+      CHECK_TRUE(wview == wsstream_view);
+      CHECK_TRUE(u16view == u16sstream_view);
+      CHECK_TRUE(u32view == u32sstream_view);
+    }
+#endif
   };
 }

test/test_string_wchar_t.cpp

@@ -5325,5 +5325,23 @@ namespace
 #endif
       CHECK_EQUAL(text.max_size(), text.size());
     }
+
+    //*************************************************************************
+#if ETL_USING_STL
+    TEST_FIXTURE(SetupFixture, test_write_string_to_std_basic_ostream)
+    {
+      Text text1 = STR("Hello World");
+
+      std::wstringstream sstream;
+
+      sstream << text1;
+
+      TextSTD sstream_string = sstream.str();
+
+      View sstream_view(sstream_string.data(), sstream_string.size());
+
+      CHECK(text1 == sstream_view);
+    }
+#endif
   };
 }

test/test_string_wchar_t_external_buffer.cpp

@@ -5680,5 +5680,24 @@ namespace
 #endif
       CHECK_EQUAL(text.max_size(), text.size());
     }
+
+    //*************************************************************************
+#if ETL_USING_STL
+    TEST_FIXTURE(SetupFixture, test_write_string_to_std_basic_ostream)
+    {
+      TextBuffer buffer1{0};
+      Text text1(STR("Hello World"), buffer1.data(), buffer1.size());
+
+      std::wstringstream sstream;
+
+      sstream << text1;
+
+      TextSTD sstream_string = sstream.str();
+
+      View sstream_view(sstream_string.data(), sstream_string.size());
+
+      CHECK(text1 == sstream_view);
+    }
+#endif
   };
 }