tools

commit 192ef420c79a4a4097b5decce589e676bc1c44ca
parent 4778ae6d8e04f1dbfb40c559d75b4b34a085224a
Author: Morel Bérenger <berengermorel76@gmail.com>
Date:   Fri, 14 Aug 2020 07:36:09 +0200

introduce my old unique_res<> template

I wrote this code years ago when I noticed that
std::unique_ptr<> takes, in practice, the size of 2
pointers when used to manage C structures, because the
destructor must, for a reason I don't understand, be setup
at construction time instead of statically at build time.
My implementation also allows to use RAII on non-pointer
resources, like file descriptors or OpenGL identifiers.

Diffstat:
A
btl/src/memory.hpp
 | 
122
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
M
btl/src/string.cpp
 | 
4
++--

2 files changed, 124 insertions(+), 2 deletions(-)
diff --git a/btl/src/memory.hpp b/btl/src/memory.hpp
@@ -0,0 +1,122 @@
+#ifndef MEMORY_HPP
+#define MEMORY_HPP
+
+#include <utility>
+
+template <typename T>
+void generic_free( T* p )
+{
+	free( p );
+}
+
+template
+<
+	typename T,
+	T INVALID_VAL,
+	void(*DTOR)(T)
+>
+class weak_res
+{
+protected:
+	typedef weak_res<T,INVALID_VAL,DTOR> COMPLETE_TYPE;
+	T m_data;
+public:
+	bool valid( void ) const
+	{
+		return m_data != INVALID_VAL;
+	}
+
+	bool operator==( COMPLETE_TYPE const& other ) const
+	{
+		return m_data == other.m_data;
+	}
+
+	bool operator==( T const& other ) const
+	{
+		return m_data == other;
+	}
+
+	bool operator!=( COMPLETE_TYPE const& other ) const
+	{
+		return m_data != other.m_data;
+	}
+
+	bool operator!=( T const& other ) const
+	{
+		return m_data != other;
+	}
+
+	const T get( void ) const
+	{
+		return m_data;
+	}
+};
+
+template
+<
+	typename T,
+	T INVALID_VAL,
+	void(*DTOR)(T)
+>
+class unique_res : public weak_res<T,INVALID_VAL,DTOR>
+//class unique_res
+{
+	typedef unique_res<T,INVALID_VAL,DTOR> UNIQUE_TYPE;
+public:
+	unique_res( UNIQUE_TYPE const& ) = delete;
+	UNIQUE_TYPE& operator=( UNIQUE_TYPE const& other ) = delete;
+
+	unique_res( void )
+	{
+		this->m_data = INVALID_VAL;
+	}
+
+	unique_res( UNIQUE_TYPE && other )
+	{
+		this->m_data = other.m_data;
+		other.m_data = INVALID_VAL;
+	}
+
+	unique_res( T && src )
+	{
+		this->m_data = src;
+		src = INVALID_VAL;
+	}
+
+	UNIQUE_TYPE& operator=( UNIQUE_TYPE && other )
+	{
+		clear();
+		std::swap( this->m_data, other.m_data );
+		return *this;
+	}
+
+	UNIQUE_TYPE& operator=( T && other )
+	{
+		clear();
+		std::swap( this->m_data, other );
+		return *this;
+	}
+
+	T release( void )
+	{
+		T ret = this->m_data;
+		this->m_data = INVALID_VAL;
+		return ret;
+	}
+
+	void clear( void )
+	{
+		if( INVALID_VAL != this->m_data )
+		{
+			DTOR( this->m_data );
+			this->m_data = INVALID_VAL;
+		}
+	}
+
+	~unique_res( void )
+	{
+		clear();
+	}
+};
+
+#endif
diff --git a/btl/src/string.cpp b/btl/src/string.cpp
@@ -1,5 +1,4 @@
 #include <utility>
-#include <memory>
 
 #include <string.h>
 #include <stddef.h>
@@ -11,6 +10,7 @@
 
 #include "vector.hpp"
 #include "string.hpp"
+#include "memory.hpp"
 
 string make_string( char const* str )
 {
@@ -23,7 +23,7 @@ string make_string( wchar_t const* str )
 {
 	string ret;
 	size_t str_sz = wcslen( str );
-	std::unique_ptr<char> temp( static_cast<char*>(  malloc( str_sz +1 ) ) );
+	unique_res<char*,nullptr,generic_free> temp( static_cast<char*>(  malloc( str_sz +1 ) ) );
 	size_t sz = wcstombs( temp.get(), str, str_sz );
 	assert( sz == str_sz );
 	ret.assign( temp.get(), temp.get() + sz );