remove more C++11 work-arounds (#642)

* is_trivially_copyable for old Intel compiler

* need to stick with coda_oss::make_unique for now because of old Intel compiler

* Revert "need to stick with coda_oss::make_unique for now because of old Intel compiler"

This reverts commit 76ebc4f.

* trying to get std::make_unique with old Intel compiler

* the old Intel compiler does have std::make_unique with C++14

* remove some compiler warnings/diagnostics ... which can cause build failures, depending on options.

* don't need to turn off various GCC warnings anymore

* compile modules/c++ with -Wall

* build cleanly with -Wpedantic

* enable more GCC warnings

* use the standard (not legacy) C pre-processor doesn't allow "mdspan" to work

* still building with older GCC :-(

* remove #ifdefs for SGI and Sun

* WIN32 -> _WIN32

* remove str::ui16string, in C++14, std::u16string should be fully supported.

* save away result of mString.data()

* merge develop/reduce-compiler-warnings

* no longer using the old compilers

modules/c++/coda_oss/include/coda_oss/CPlusPlus.h

@@ -53,16 +53,6 @@
     #endif  // __INTEL_COMPILER
 #endif // CODA_OSS_cplusplus
 
-#if CODA_OSS_cplusplus < 201402L
-    // oops ... try to fix
-    #if defined(__INTEL_COMPILER) && (__INTEL_COMPILER_BUILD_DATE >= 20151021)
-        // __cplusplus is 201300, not 201402L
-        // Enough C++14, at least with our std/ work-arounds
-        #undef CODA_OSS_cplusplus
-        #define CODA_OSS_cplusplus 201402L
-     #endif
-#endif  // CODA_OSS_cplusplus
-
 #if CODA_OSS_cplusplus < 202002L
     // oops ... try to fix
     #if defined(__GNUC__) && (__cplusplus >= 201709L)  // note > C++ 17 of 201703L

modules/c++/coda_oss/include/coda_oss/optional_.h

@@ -63,27 +63,21 @@ class optional final
     using value_type = T;
 
 #if defined(_MSC_VER) && _PREFAST_  // Visual Studio /analyze
-    __pragma(warning(push)) __pragma(warning(
-            disable : 26495))  // Variable '...' is uninitialized. Always
-                               // initialize a member variable(type.6).
+    __pragma(warning(push)) __pragma(warning(disable : 26495))  // Variable '...' is uninitialized. Always initialize a member variable(type.6).
 #endif
-            optional() noexcept
+    optional() noexcept
     {
     }
 #if defined(_MSC_VER) && _PREFAST_
     __pragma(warning(pop))
 #endif
-            optional(const value_type& v) :
-        value_(v), has_value_(true)
+    optional(const value_type& v) : value_(v), has_value_(true)
     {
     }
 #if defined(_MSC_VER) && _PREFAST_  // Visual Studio /analyze
-    __pragma(warning(push)) __pragma(warning(
-            disable : 26495))  // Variable '...' is uninitialized. Always
-                               // initialize a member variable(type.6).
+    __pragma(warning(push)) __pragma(warning(disable : 26495))  // Variable '...' is uninitialized. Always initialize a member variable(type.6).
 #endif
-            optional(const optional& other) :
-        has_value_(other.has_value_)
+    optional(const optional& other) : has_value_(other.has_value_)
     {
         if (has_value())
         {
@@ -94,18 +88,15 @@ class optional final
     __pragma(warning(pop))
 #endif
 
-            template <
-                    typename... Args>  // https://en.cppreference.com/w/cpp/utility/Optional/emplace
-            T& emplace(Args&&... args)
+    template <typename... Args>  // https://en.cppreference.com/w/cpp/utility/Optional/emplace
+    T& emplace(Args&&... args)
     {
         value_ = value_type(std::forward<Args>(args)...);
         has_value_ = true;
         return value_;
     }
 
-    template <
-            typename U =
-                    T>  // https://en.cppreference.com/w/cpp/utility/optional/operator%3D
+    template <typename U = T>  // https://en.cppreference.com/w/cpp/utility/optional/operator%3D
     optional& operator=(U&& value) noexcept
     {
         value_ = std::forward<U>(value);
@@ -163,11 +154,10 @@ class optional final
                          // contains a value!"
     }
 
-    const T& operator*() const&
+    const T& operator*() const& noexcept
     {
         assert(has_value());
-        return value_;  // "This operator does not check whether the optional
-                        // contains a value!"
+        return value_;  // "This operator does not check whether the optional contains a value!"
     }
     T& operator*() &
     {

modules/c++/coda_oss/include/coda_oss/type_traits.h

@@ -29,21 +29,7 @@
 #include "coda_oss/namespace_.h"
 namespace coda_oss
 {
-// workaround missing "is_trivially_copyable" in g++ < 5.0
-// https://stackoverflow.com/a/31798726/8877
-#if defined(__GNUC__) && (__GNUC__ < 5)
-template <typename T>
-struct is_trivially_copyable final
-{
-    // This old Intel compiler has enough C++14 for our needs; see CPlusPlus.h
-    #if !(defined(__INTEL_COMPILER) && (__INTEL_COMPILER_BUILD_DATE <= 20151021))
-        static_assert(CODA_OSS_cplusplus < 201402L, "C++14 must have is_trivially_copyable.");
-    #endif
-    static constexpr bool value = __has_trivial_copy(T);
-};
-#else
 using std::is_trivially_copyable;
-#endif
 }
 
 #endif  // CODA_OSS_coda_oss_type_traits_h_INCLUDED_

modules/c++/str/include/str/EncodedStringView.h

@@ -110,7 +110,7 @@ class CODA_OSS_API EncodedStringView final
     std::wstring wstring() const; // UTF-16 on Windows, UTF-32 on Linux
 
     // These are for "advanced" use, most "normal" code should use the routines above.
-    std::string::const_pointer c_str() const
+    std::string::const_pointer c_str() const noexcept
     {
         return mString.data();
     }
@@ -122,7 +122,7 @@ class CODA_OSS_API EncodedStringView final
     {
         return mIsUtf8 ? nullptr : cast<str::W1252string::const_pointer>(c_str());
     }
-    size_t size() const
+    size_t size() const noexcept
     {
         return mString.size();
     }

modules/c++/xml.lite/include/xml/lite/Attributes.h

@@ -31,6 +31,7 @@
 #include "except/Exception.h"
 #include "xml/lite/QName.h"
 #include "str/Convert.h"
+#include "gsl/gsl.h"
 
 /*!
  *  \file Attributes.h
@@ -330,7 +331,7 @@ struct Attributes final
     }
     std::string operator[](const xml::lite::QName& name) const
     {
-        const size_t idx = getIndex(name);
+        const auto idx = gsl::narrow<size_t>(getIndex(name));
         return mAttributes[idx].getValue();
     }
 
@@ -348,7 +349,7 @@ struct Attributes final
     }
     std::string operator[](const std::string& s) const
     {
-        const size_t idx = getIndex(s);
+        const auto idx = gsl::narrow<size_t>(getIndex(s));
         return mAttributes[idx].getValue();
     }