Add constructors

Author: gammasoft71

src/xtd.core/include/xtd/io/memory_stream.hpp

@@ -38,7 +38,8 @@ namespace xtd {
       /// @remarks The xtd::io::memory_stream::can_read, xtd::io::memory_stream::can_seek, and xtd::io::memory_stream::can_write properties are all set to true.
       /// @remarks The capacity of the current stream automatically increases when you use the xtd::io::memory_stream::set_length method to set the length to a value larger than the capacity of the current stream.
       /// @remarks This constructor exposes the underlying stream, which xtd::io::memory_stream::get_buffer returns.
-      memory_stream() {}
+      memory_stream();
+      memory_stream(xtd::size capacity);
       /// @}
 
       /// @name Public Properties

src/xtd.core/src/xtd/io/memory_stream.cpp

@@ -4,6 +4,13 @@
 using namespace xtd;
 using namespace xtd::io;
 
+memory_stream::memory_stream() {
+}
+
+memory_stream::memory_stream(xtd::size capacity) {
+  this->capacity(capacity);
+}
+
 bool memory_stream::can_read() const noexcept {
   return true;
 }