comparison DEPENDENCIES/generic/include/boost/wave/util/cpp_ifblock.hpp @ 16:2665513ce2d3

Add boost headers

+/*=============================================================================
+    Boost.Wave: A Standard compliant C++ preprocessor library
+
+    http://www.boost.org/
+
+    Copyright (c) 2001-2012 Hartmut Kaiser. Distributed under the Boost
+    Software License, Version 1.0. (See accompanying file
+    LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+=============================================================================*/
+
+#if !defined(CPP_IFBLOCK_HPP_D4676B36_00C5_41F4_BC9F_9CBBAE3B8006_INCLUDED)
+#define CPP_IFBLOCK_HPP_D4676B36_00C5_41F4_BC9F_9CBBAE3B8006_INCLUDED
+
+#include <stack>
+#include <boost/wave/wave_config.hpp>
+
+// this must occur after all of the includes and before any code appears
+#ifdef BOOST_HAS_ABI_HEADERS
+#include BOOST_ABI_PREFIX
+#endif
+
+///////////////////////////////////////////////////////////////////////////////
+namespace boost {
+namespace wave {
+namespace util {
+
+///////////////////////////////////////////////////////////////////////////////
+// the class if_blocks handles recursive conditional compilation contexts
+class if_block
+{
+public:
+    if_block() :
+        status(true), some_part_status(true), 
+        enclosing_status(true), is_in_else(false)
+    {
+    }
+    if_block(bool status_, bool enclosing_status_) : 
+        status(status_), 
+        some_part_status(status_),
+        enclosing_status(enclosing_status_),
+        is_in_else(false)
+    {
+    }
+
+    void set_status(bool status_) 
+    { 
+        status = status_; 
+        if (status_) 
+            some_part_status = true; 
+    }
+    bool get_status() const { return status; }
+    bool get_some_part_status() const { return some_part_status; }
+    bool get_enclosing_status() const { return enclosing_status; }
+    bool get_in_else() const { return is_in_else; }
+    void set_in_else() { is_in_else = true; }
+
+private:
+   bool status;             // Current block is true
+   bool some_part_status;   // One of the preceding or current #if/#elif was true
+   bool enclosing_status;   // Enclosing #if block is true
+   bool is_in_else;         // Inside the #else part
+};
+
+///////////////////////////////////////////////////////////////////////////////
+// stack of conditional compilation contexts
+class if_block_stack 
+:   private std::stack<if_block> 
+{
+public:
+    typedef std::stack<if_block>::size_type size_type;
+
+    void enter_if_block(bool new_status)
+    {
+    // If enclosing block is false, then this block is also false
+        bool enclosing_status = get_status();
+        this->push (value_type (new_status && enclosing_status, enclosing_status));
+    }
+    bool enter_elif_block(bool new_status)
+    {
+        if (!is_inside_ifpart())
+            return false;       // #elif without matching #if
+
+        if (get_enclosing_status()) {
+            if (get_status()) {
+            // entered a (false) #elif block from a true block
+                this->top().set_status(false);
+            } 
+            else if (new_status && !this->top().get_some_part_status()) {
+            // Entered true #elif block and no previous block was true
+                this->top().set_status(new_status);
+            }
+        }
+        return true;
+    }
+    bool enter_else_block()
+    {
+        if (!is_inside_ifpart())
+            return false;       // #else without matching #if
+
+        if (get_enclosing_status()) {
+            if (!this->top().get_some_part_status()) {
+            // Entered (true) #else block and no previous block was true
+                this->top().set_status(true);
+            } 
+            else if (get_status()) {
+            // Entered (false) #else block from true block
+                this->top().set_status(false);
+            }
+
+        // Set else flag
+            this->top().set_in_else();
+        }
+        return true;
+    }
+    bool exit_if_block()
+    {
+        if (0 == this->size())
+            return false;   // #endif without matching #if
+
+        this->pop();
+        return true;
+    }
+
+// return, whether the top (innermost) condition is true or false
+    bool get_status() const
+    { 
+        return 0 == this->size() || this->top().get_status(); 
+    }
+    bool get_some_part_status() const
+    { 
+        return 0 == this->size() || this->top().get_some_part_status(); 
+    }
+    bool get_enclosing_status() const
+    {
+        return 0 == this->size() || this->top().get_enclosing_status();
+    }
+
+    size_type get_if_block_depth() const { return this->size(); }
+
+protected:
+    bool is_inside_ifpart() const
+    {
+        return 0 != this->size() && !this->top().get_in_else();
+    }
+    bool is_inside_elsepart() const
+    {
+        return 0 != this->size() && this->top().get_in_else();
+    }
+};
+
+///////////////////////////////////////////////////////////////////////////////
+}   // namespace util
+}   // namespace wave
+}   // namespace boost
+
+// the suffix header occurs after all of the code
+#ifdef BOOST_HAS_ABI_HEADERS
+#include BOOST_ABI_SUFFIX
+#endif
+
+#endif // !defined(CPP_IFBLOCK_HPP_D4676B36_00C5_41F4_BC9F_9CBBAE3B8006_INCLUDED)