diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7397fe2..cb5911c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -3,10 +3,10 @@ cmake_minimum_required(VERSION 2.8.7)
 project(GSL CXX)
 
 set(GSL_HEADERS
-    "include/gsl.h"
-    "include/gsl_assert.h"
-    "include/span.h"
-    "include/string_span.h"
+    "gsl/gsl"
+    "gsl/gsl_assert"
+    "gsl/span"
+    "gsl/string_span"
 )
 
 include_directories(
diff --git a/README.md b/README.md
index 3c440c2..58bb46c 100644
--- a/README.md
+++ b/README.md
@@ -6,10 +6,10 @@ This repo contains Microsoft's implementation of GSL.
 
 The library includes types like `span<T>`, `string_span`, `owner<>` and others.
 
-The entire implementation is provided inline in the headers under the [include](./include) directory. The implementation generally assumes a platform that implements C++14 support. There are specific workarounds to support MSVC 2013 and 2015.
+The entire implementation is provided inline in the headers under the [gsl](./gsl) directory. The implementation generally assumes a platform that implements C++14 support. There are specific workarounds to support MSVC 2013 and 2015.
 
-While some types have been broken out into their own headers (e.g. [include/span.h](./include/span.h)),
-it is simplest to just include [gsl.h](./include/gsl.h) and gain access to the entire library.
+While some types have been broken out into their own headers (e.g. [gsl/span](./gsl/span)),
+it is simplest to just include [gsl/gsl](./gsl/gsl) and gain access to the entire library.
 
 > NOTE: We encourage contributions that improve or refine any of the types in this library as well as ports to
 other platforms. Please see [CONTRIBUTING.md](./CONTRIBUTING.md) for more information about contributing.
@@ -66,5 +66,19 @@ All tests should pass - indicating your platform is fully supported and you are
 ## Using the libraries
 As the types are entirely implemented inline in headers, there are no linking requirements.
 
-Just place the contents of the [include](./include) directory within your source tree so it is available
-to your compiler, then include the appropriate headers in your program, and away you go!
+You can copy the [gsl](./gsl) directory into your source tree so it is available
+to your compiler, then include the appropriate headers in your program.
+
+Alternatively set your compiler's *include path* flag to point to the GSL development folder (`c:\GSL` in the example above) or installation folder (after running the install). Eg.
+
+MSVC++
+
+    /I c:\GSL
+
+GCC/clang
+
+    -I$HOME/dev/GSL
+
+Include the library using:
+
+    #include <gsl/gsl>
diff --git a/include/gsl.h b/gsl/gsl
similarity index 94%
rename from include/gsl.h
rename to gsl/gsl
index 8e00a44..656ebe0 100644
--- a/include/gsl.h
+++ b/gsl/gsl
@@ -19,11 +19,11 @@
 #ifndef GSL_GSL_H
 #define GSL_GSL_H
 
-#include "gsl_assert.h"  // Ensures/Expects
-#include "gsl_util.h"    // finally()/narrow()/narrow_cast()...
-#include "multi_span.h"  // multi_span, strided_span...
-#include "span.h"        // span
-#include "string_span.h" // zstring, string_span, zstring_builder...
+#include "gsl_assert"  // Ensures/Expects
+#include "gsl_util"    // finally()/narrow()/narrow_cast()...
+#include "multi_span"  // multi_span, strided_span...
+#include "span"        // span
+#include "string_span" // zstring, string_span, zstring_builder...
 #include <memory>
 
 #ifdef _MSC_VER
diff --git a/include/gsl_assert.h b/gsl/gsl_assert
similarity index 100%
rename from include/gsl_assert.h
rename to gsl/gsl_assert
diff --git a/include/gsl_byte.h b/gsl/gsl_byte
similarity index 100%
rename from include/gsl_byte.h
rename to gsl/gsl_byte
diff --git a/include/gsl_util.h b/gsl/gsl_util
similarity index 98%
rename from include/gsl_util.h
rename to gsl/gsl_util
index 92a795b..4a0dabe 100644
--- a/include/gsl_util.h
+++ b/gsl/gsl_util
@@ -19,7 +19,7 @@
 #ifndef GSL_UTIL_H
 #define GSL_UTIL_H
 
-#include "gsl_assert.h" // Ensures/Expects
+#include "gsl_assert" // Ensures/Expects
 #include <array>
 #include <exception>
 #include <type_traits>
diff --git a/include/multi_span.h b/gsl/multi_span
similarity index 99%
rename from include/multi_span.h
rename to gsl/multi_span
index b31909d..5ddf6fa 100644
--- a/include/multi_span.h
+++ b/gsl/multi_span
@@ -19,9 +19,9 @@
 #ifndef GSL_MULTI_SPAN_H
 #define GSL_MULTI_SPAN_H
 
-#include "gsl_assert.h"
-#include "gsl_byte.h"
-#include "gsl_util.h"
+#include "gsl_assert"
+#include "gsl_byte"
+#include "gsl_util"
 #include <algorithm>
 #include <array>
 #include <cassert>
diff --git a/include/span.h b/gsl/span
similarity index 99%
rename from include/span.h
rename to gsl/span
index 5b2e427..3b8318d 100644
--- a/include/span.h
+++ b/gsl/span
@@ -20,9 +20,9 @@
 #ifndef GSL_SPAN_H
 #define GSL_SPAN_H
 
-#include "gsl_assert.h"
-#include "gsl_byte.h"
-#include "gsl_util.h"
+#include "gsl_assert"
+#include "gsl_byte"
+#include "gsl_util"
 #include <array>
 #include <iterator>
 #include <limits>
@@ -681,10 +681,13 @@ as_writeable_bytes(span<ElementType, Extent> s) noexcept
 #undef noexcept
 
 #ifdef _MSC_VER
-#pragma warning(pop)
 #pragma pop_macro("noexcept")
 #endif
 
 #endif // GSL_THROW_ON_CONTRACT_VIOLATION
 
+#ifdef _MSC_VER
+#pragma warning(pop)
+#endif
+
 #endif // GSL_SPAN_H
diff --git a/include/string_span.h b/gsl/string_span
similarity index 99%
rename from include/string_span.h
rename to gsl/string_span
index e18e07a..fa3d2ff 100644
--- a/include/string_span.h
+++ b/gsl/string_span
@@ -19,9 +19,9 @@
 #ifndef GSL_STRING_SPAN_H
 #define GSL_STRING_SPAN_H
 
-#include "gsl_assert.h"
-#include "gsl_util.h"
-#include "span.h"
+#include "gsl_assert"
+#include "gsl_util"
+#include "span"
 #include <cstdint>
 #include <cstring>
 #include <string>
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 79931f7..3c3125e 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -9,7 +9,7 @@ endif()
 add_subdirectory(unittest-cpp)
 
 include_directories(
-    ../include
+    ..
     ./unittest-cpp
 )
 
@@ -33,7 +33,7 @@ else()
 endif()
 
 function(add_gsl_test name)
-    add_executable(${name} ${name}.cpp ../include/gsl.h ../include/gsl_assert.h ../include/gsl_util.h ../include/multi_span.h ../include/span.h ../include/string_span.h)
+    add_executable(${name} ${name}.cpp ../gsl/gsl ../gsl/gsl_assert ../gsl/gsl_util ../gsl/multi_span ../gsl/span ../gsl/string_span)
     target_link_libraries(${name} UnitTest++)
     install(TARGETS ${name}
         RUNTIME DESTINATION bin
diff --git a/tests/assertion_tests.cpp b/tests/assertion_tests.cpp
index acd381a..a251200 100644
--- a/tests/assertion_tests.cpp
+++ b/tests/assertion_tests.cpp
@@ -15,7 +15,7 @@
 ///////////////////////////////////////////////////////////////////////////////
 
 #include <UnitTest++/UnitTest++.h> 
-#include <gsl.h>
+#include <gsl/gsl>
 
 using namespace gsl;
 
diff --git a/tests/at_tests.cpp b/tests/at_tests.cpp
index 1a9f814..008fddf 100644
--- a/tests/at_tests.cpp
+++ b/tests/at_tests.cpp
@@ -15,7 +15,7 @@
 ///////////////////////////////////////////////////////////////////////////////
 
 #include <UnitTest++/UnitTest++.h> 
-#include <gsl.h>
+#include <gsl/gsl>
 #include <vector>
 #include <initializer_list>
 
diff --git a/tests/bounds_tests.cpp b/tests/bounds_tests.cpp
index 736a85c..d10bf6d 100644
--- a/tests/bounds_tests.cpp
+++ b/tests/bounds_tests.cpp
@@ -15,7 +15,7 @@
 ///////////////////////////////////////////////////////////////////////////////
 
 #include <UnitTest++/UnitTest++.h> 
-#include <multi_span.h>
+#include <gsl/multi_span>
 #include <vector>
 
 using namespace std;
diff --git a/tests/byte_tests.cpp b/tests/byte_tests.cpp
index 5d4e7f6..f2f8026 100644
--- a/tests/byte_tests.cpp
+++ b/tests/byte_tests.cpp
@@ -15,7 +15,7 @@
 ///////////////////////////////////////////////////////////////////////////////
 
 #include <UnitTest++/UnitTest++.h>
-#include <gsl_byte.h>
+#include <gsl/gsl_byte>
 
 #include <iostream>
 #include <list>
diff --git a/tests/multi_span_tests.cpp b/tests/multi_span_tests.cpp
index 003d236..f04ba84 100644
--- a/tests/multi_span_tests.cpp
+++ b/tests/multi_span_tests.cpp
@@ -15,7 +15,7 @@
 ///////////////////////////////////////////////////////////////////////////////
 
 #include <UnitTest++/UnitTest++.h>
-#include <multi_span.h>
+#include <gsl/multi_span>
 
 #include <iostream>
 #include <list>
diff --git a/tests/notnull_tests.cpp b/tests/notnull_tests.cpp
index 67b478a..526b074 100644
--- a/tests/notnull_tests.cpp
+++ b/tests/notnull_tests.cpp
@@ -15,7 +15,7 @@
 ///////////////////////////////////////////////////////////////////////////////
 
 #include <UnitTest++/UnitTest++.h> 
-#include <gsl.h>
+#include <gsl/gsl>
 #include <vector>
 
 using namespace gsl;
diff --git a/tests/owner_tests.cpp b/tests/owner_tests.cpp
index 47c223a..6680981 100644
--- a/tests/owner_tests.cpp
+++ b/tests/owner_tests.cpp
@@ -15,7 +15,7 @@
 ///////////////////////////////////////////////////////////////////////////////
 
 #include <UnitTest++/UnitTest++.h> 
-#include <gsl.h>
+#include <gsl/gsl>
 #include <functional>
 
 using namespace gsl;
diff --git a/tests/span_tests.cpp b/tests/span_tests.cpp
index 5e71410..05386b2 100644
--- a/tests/span_tests.cpp
+++ b/tests/span_tests.cpp
@@ -15,7 +15,7 @@
 ///////////////////////////////////////////////////////////////////////////////
 
 #include <UnitTest++/UnitTest++.h>
-#include <span.h>
+#include <gsl/span>
 
 #include <iostream>
 #include <list>
diff --git a/tests/strided_span_tests.cpp b/tests/strided_span_tests.cpp
index b81a5e7..86666d1 100644
--- a/tests/strided_span_tests.cpp
+++ b/tests/strided_span_tests.cpp
@@ -15,7 +15,7 @@
 ///////////////////////////////////////////////////////////////////////////////
 
 #include <UnitTest++/UnitTest++.h> 
-#include <multi_span.h>
+#include <gsl/multi_span>
 
 #include <string>
 #include <vector>
diff --git a/tests/string_span_tests.cpp b/tests/string_span_tests.cpp
index 876886a..7e623f3 100644
--- a/tests/string_span_tests.cpp
+++ b/tests/string_span_tests.cpp
@@ -16,8 +16,9 @@
 
 #include <UnitTest++/UnitTest++.h>
 #include <cstdlib>
-#include <string_span.h>
+#include <gsl/string_span>
 #include <vector>
+#include <map>
 
 using namespace std;
 using namespace gsl;
@@ -942,7 +943,13 @@ SUITE(string_span_tests)
                 CHECK(*(str + 3) == L'\0');
             }
         }
+    }
 
+    TEST(Issue305)
+    {
+        std::map<gsl::cstring_span<>, int> foo = { { "foo", 0 },{ "bar", 1 } };
+        CHECK(foo["foo"] == 0);
+        CHECK(foo["bar"] == 1);
     }
 }
 
diff --git a/tests/utils_tests.cpp b/tests/utils_tests.cpp
index 11582de..9f4ba02 100644
--- a/tests/utils_tests.cpp
+++ b/tests/utils_tests.cpp
@@ -15,7 +15,7 @@
 ///////////////////////////////////////////////////////////////////////////////
 
 #include <UnitTest++/UnitTest++.h>
-#include <gsl.h>
+#include <gsl/gsl>
 #include <functional>
 
 using namespace gsl;