From patchwork Fri Jul 16 05:53:07 2010
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Subject: [v3,constexpr] intial conversion to constexpr
Date: Thu, 15 Jul 2010 19:53:07 -0000
From: Benjamin Kosnik <bkoz@redhat.com>
X-Patchwork-Id: 59068
Message-Id: <20100715225307.18cd3099@shotwell>
To: gcc-patches@gcc.gnu.org, libstdc++@gcc.gnu.org

Here is a preliminary patch for libstdc++/* files on the constexpr
branch. As is, this doesn't compile: ICE's in atomics, some issues in
random with the max() conversion, etc. But is is a useful starting
point.

Testing the constexpr branch on linux, I see some extra fails. I'm
assuming these are expected. 

Should I work on adding in the additional tests I did some months ago
to the g++ testsuite? I suppose the branch should be documented as well.

-benjamin


2010-07-15  Benjamin Kosnik  <bkoz@redhat.com>

	* include/std/future: Preliminary constexpr additions.
	* include/std/atomic: Same.
	* include/std/chrono: Same.
	* include/bits/atomic_0.h: Same.
	* include/bits/atomic_2.h: Same.
	* include/bits/random.h: Same.

Index: include/std/future
===================================================================
--- include/std/future	(revision 162241)
+++ include/std/future	(working copy)
@@ -64,18 +64,22 @@
     no_state
   };
 
+  /// Specialization.
   template<>
     struct is_error_code_enum<future_errc> : public true_type { };
 
   /// Points to a statically-allocated object derived from error_category.
-  extern const error_category* const future_category;
+  const error_category&
+  future_category();
 
-  // TODO: requires constexpr
-  inline error_code make_error_code(future_errc __errc)
+  /// Overload for make_error_code.
+  inline error_code 
+  make_error_code(future_errc __errc)
   { return error_code(static_cast<int>(__errc), *future_category); }
 
-  // TODO: requires constexpr
-  inline error_condition make_error_condition(future_errc __errc)
+  /// Overload for make_error_condition.
+  inline error_condition 
+  make_error_condition(future_errc __errc)
   { return error_condition(static_cast<int>(__errc), *future_category); }
 
   /**
@@ -116,8 +120,22 @@
   template<typename _Res>
     class promise;
 
-  enum class launch { any, async, sync };
+  /// Launch code for futures
+  enum class launch 
+  { 
+    any, 
+    async, 
+    sync 
+  };
 
+  /// Status code for futures
+  enum class future_status 
+  {
+    ready,
+    timeout,
+    deferred
+  };
+
   template<typename _Fn, typename... _Args>
     future<typename result_of<_Fn(_Args...)>::type>
     async(launch __policy, _Fn&& __fn, _Args&&... __args);
@@ -1264,6 +1282,7 @@
       }
     };
 
+  /// swap
   template<typename _Res, typename... _ArgTypes>
     inline void
     swap(packaged_task<_Res(_ArgTypes...)>& __x,
@@ -1324,6 +1343,7 @@
       thread _M_thread;
     };
 
+  /// async 
   template<typename _Fn, typename... _Args>
     future<typename result_of<_Fn(_Args...)>::type>
     async(launch __policy, _Fn&& __fn, _Args&&... __args)
@@ -1345,6 +1365,7 @@
       return future<result_type>(__state);
     }
 
+  /// async, potential overload
   template<typename _Fn, typename... _Args>
     inline typename
     enable_if<!is_same<typename decay<_Fn>::type, launch>::value,
Index: include/std/atomic
===================================================================
--- include/std/atomic	(revision 162241)
+++ include/std/atomic	(working copy)
@@ -38,8 +38,8 @@
 # include <bits/c++0x_warning.h>
 #endif
 
-#include <bits/c++config.h>
 #include <bits/atomic_base.h>
+#include <cstddef>
 
 _GLIBCXX_BEGIN_NAMESPACE(std)
 
@@ -94,7 +94,7 @@
       atomic(const atomic&) = delete;
       atomic& operator=(const atomic&) volatile = delete;
 
-      atomic(_Tp __i) : _M_i(__i) { }
+      constexpr atomic(_Tp __i) : _M_i(__i) { }
 
       operator _Tp() const;
 
@@ -138,7 +138,7 @@
       atomic(const atomic&) = delete;
       atomic& operator=(const atomic&) volatile = delete;
 
-      atomic(_Tp* __v) : atomic_address(__v) { }
+      constexpr atomic(_Tp* __v) : atomic_address(__v) { }
 
       void
       store(_Tp*, memory_order = memory_order_seq_cst);
@@ -211,7 +211,7 @@
       atomic(const atomic&) = delete;
       atomic& operator=(const atomic&) volatile = delete;
 
-      atomic(__integral_type __i) : __base_type(__i) { }
+      constexpr atomic(__integral_type __i) : __base_type(__i) { }
 
       using __base_type::operator __integral_type;
       using __base_type::operator=;
@@ -229,7 +229,7 @@
       atomic(const atomic&) = delete;
       atomic& operator=(const atomic&) volatile = delete;
 
-      atomic(__integral_type __i) : __base_type(__i) { }
+      constexpr atomic(__integral_type __i) : __base_type(__i) { }
 
       using __base_type::operator __integral_type;
       using __base_type::operator=;
@@ -247,7 +247,7 @@
       atomic(const atomic&) = delete;
       atomic& operator=(const atomic&) volatile = delete;
 
-      atomic(__integral_type __i) : __base_type(__i) { }
+      constexpr atomic(__integral_type __i) : __base_type(__i) { }
 
       using __base_type::operator __integral_type;
       using __base_type::operator=;
@@ -265,7 +265,7 @@
       atomic(const atomic&) = delete;
       atomic& operator=(const atomic&) volatile = delete;
 
-      atomic(__integral_type __i) : __base_type(__i) { }
+      constexpr atomic(__integral_type __i) : __base_type(__i) { }
 
       using __base_type::operator __integral_type;
       using __base_type::operator=;
@@ -283,7 +283,7 @@
       atomic(const atomic&) = delete;
       atomic& operator=(const atomic&) volatile = delete;
 
-      atomic(__integral_type __i) : __base_type(__i) { }
+      constexpr atomic(__integral_type __i) : __base_type(__i) { }
 
       using __base_type::operator __integral_type;
       using __base_type::operator=;
@@ -301,7 +301,7 @@
       atomic(const atomic&) = delete;
       atomic& operator=(const atomic&) volatile = delete;
 
-      atomic(__integral_type __i) : __base_type(__i) { }
+      constexpr atomic(__integral_type __i) : __base_type(__i) { }
 
       using __base_type::operator __integral_type;
       using __base_type::operator=;
@@ -319,7 +319,7 @@
       atomic(const atomic&) = delete;
       atomic& operator=(const atomic&) volatile = delete;
 
-      atomic(__integral_type __i) : __base_type(__i) { }
+      constexpr atomic(__integral_type __i) : __base_type(__i) { }
 
       using __base_type::operator __integral_type;
       using __base_type::operator=;
@@ -337,7 +337,7 @@
       atomic(const atomic&) = delete;
       atomic& operator=(const atomic&) volatile = delete;
 
-      atomic(__integral_type __i) : __base_type(__i) { }
+      constexpr atomic(__integral_type __i) : __base_type(__i) { }
 
       using __base_type::operator __integral_type;
       using __base_type::operator=;
@@ -355,7 +355,7 @@
       atomic(const atomic&) = delete;
       atomic& operator=(const atomic&) volatile = delete;
 
-      atomic(__integral_type __i) : __base_type(__i) { }
+      constexpr atomic(__integral_type __i) : __base_type(__i) { }
 
       using __base_type::operator __integral_type;
       using __base_type::operator=;
@@ -373,7 +373,7 @@
       atomic(const atomic&) = delete;
       atomic& operator=(const atomic&) volatile = delete;
 
-      atomic(__integral_type __i) : __base_type(__i) { }
+      constexpr atomic(__integral_type __i) : __base_type(__i) { }
 
       using __base_type::operator __integral_type;
       using __base_type::operator=;
@@ -391,7 +391,7 @@
       atomic(const atomic&) = delete;
       atomic& operator=(const atomic&) volatile = delete;
 
-      atomic(__integral_type __i) : __base_type(__i) { }
+      constexpr atomic(__integral_type __i) : __base_type(__i) { }
 
       using __base_type::operator __integral_type;
       using __base_type::operator=;
@@ -409,7 +409,7 @@
       atomic(const atomic&) = delete;
       atomic& operator=(const atomic&) volatile = delete;
 
-      atomic(__integral_type __i) : __base_type(__i) { }
+      constexpr atomic(__integral_type __i) : __base_type(__i) { }
 
       using __base_type::operator __integral_type;
       using __base_type::operator=;
@@ -427,7 +427,7 @@
       atomic(const atomic&) = delete;
       atomic& operator=(const atomic&) volatile = delete;
 
-      atomic(__integral_type __i) : __base_type(__i) { }
+      constexpr atomic(__integral_type __i) : __base_type(__i) { }
 
       using __base_type::operator __integral_type;
       using __base_type::operator=;
@@ -445,7 +445,7 @@
       atomic(const atomic&) = delete;
       atomic& operator=(const atomic&) volatile = delete;
 
-      atomic(__integral_type __i) : __base_type(__i) { }
+      constexpr atomic(__integral_type __i) : __base_type(__i) { }
 
       using __base_type::operator __integral_type;
       using __base_type::operator=;
@@ -463,7 +463,7 @@
       atomic(const atomic&) = delete;
       atomic& operator=(const atomic&) volatile = delete;
 
-      atomic(__integral_type __i) : __base_type(__i) { }
+      constexpr atomic(__integral_type __i) : __base_type(__i) { }
 
       using __base_type::operator __integral_type;
       using __base_type::operator=;
@@ -481,7 +481,7 @@
       atomic(const atomic&) = delete;
       atomic& operator=(const atomic&) volatile = delete;
 
-      atomic(__integral_type __i) : __base_type(__i) { }
+      constexpr atomic(__integral_type __i) : __base_type(__i) { }
 
       using __base_type::operator __integral_type;
       using __base_type::operator=;
Index: include/std/chrono
===================================================================
--- include/std/chrono	(revision 162241)
+++ include/std/chrono	(working copy)
@@ -173,15 +173,15 @@
     template<typename _Rep>
       struct duration_values
       {
-        static const _Rep
+        static constexpr _Rep
         zero()
         { return _Rep(0); }
         
-        static const _Rep
+        static constexpr _Rep
         max()
         { return numeric_limits<_Rep>::max(); }
         
-        static const _Rep
+        static constexpr _Rep
         min()
         { return numeric_limits<_Rep>::min(); }
       };
@@ -209,20 +209,20 @@
         typedef _Period period;
         
         // 20.8.3.1 construction / copy / destroy
-	duration() = default;
+	constexpr duration() = default;
 
         template<typename _Rep2, typename = typename
 	       enable_if<is_convertible<_Rep2, rep>::value
 			 && (treat_as_floating_point<rep>::value
 			     || !treat_as_floating_point<_Rep2>::value)>::type>
-          explicit duration(const _Rep2& __rep)
+          constexpr explicit duration(const _Rep2& __rep)
           : __r(static_cast<rep>(__rep)) { }
 
         template<typename _Rep2, typename _Period2, typename = typename
 	       enable_if<treat_as_floating_point<rep>::value 
 			 || (ratio_divide<_Period2, period>::type::den == 1
 			     && !treat_as_floating_point<_Rep2>::value)>::type>
-          duration(const duration<_Rep2, _Period2>& __d)
+          constexpr duration(const duration<_Rep2, _Period2>& __d)
           : __r(duration_cast<duration>(__d).count()) { }
 
 	~duration() = default;
@@ -230,16 +230,16 @@
 	duration& operator=(const duration&) = default;
 
         // 20.8.3.2 observer
-        rep
+        constexpr rep
         count() const
         { return __r; }
 
         // 20.8.3.3 arithmetic
-        duration
+        constexpr duration
         operator+() const 
         { return *this; }
 
-        duration
+        constexpr duration
         operator-() const
         { return duration(-__r); }
 
@@ -313,16 +313,15 @@
 	  }
 
         // 20.8.3.4 special values
-        // TODO: These should be constexprs.
-        static const duration
+        static constexpr duration
         zero()
         { return duration(duration_values<rep>::zero()); }
 
-        static const duration
+        static constexpr duration
         min()
         { return duration(duration_values<rep>::min()); }
       
-        static const duration
+        static constexpr duration
         max()
         { return duration(duration_values<rep>::max()); }
 
@@ -530,12 +529,11 @@
 	}
 	
 	// special values
-	// TODO: These should be constexprs.
-	static const time_point
+	static constexpr time_point
 	min()
 	{ return time_point(duration::min()); }
 	
-	static const time_point
+	static constexpr time_point
 	max()
 	{ return time_point(duration::max()); }
 	
@@ -660,13 +658,10 @@
             chrono::seconds(__t)));
       }
 
-      // TODO: requires constexpr
-      /*  
       static_assert(
         system_clock::duration::min() < 
         system_clock::duration::zero(), 
         "a clock's minimum duration cannot be less than its epoch");
-      */
     };
 
 #ifdef _GLIBCXX_USE_CLOCK_MONOTONIC
Index: include/bits/atomic_0.h
===================================================================
--- include/bits/atomic_0.h	(revision 162241)
+++ include/bits/atomic_0.h	(working copy)
@@ -1,6 +1,6 @@
 // -*- C++ -*- header.
 
-// Copyright (C) 2008, 2009
+// Copyright (C) 2008, 2009, 2010
 // Free Software Foundation, Inc.
 //
 // This file is part of the GNU ISO C++ Library.  This library is free
@@ -111,7 +111,7 @@
     atomic_address(const atomic_address&) = delete;
     atomic_address& operator=(const atomic_address&) volatile = delete;
 
-    atomic_address(void* __v) { _M_i = __v; }
+    constexpr atomic_address(void* __v) { _M_i = __v; }
 
     bool
     is_lock_free() const
@@ -255,7 +255,7 @@
       __atomic_base& operator=(const __atomic_base&) volatile = delete;
 
       // Requires __integral_type convertible to _M_base._M_i.
-      __atomic_base(__integral_type __i) { _M_i = __i; }
+      constexpr __atomic_base(__integral_type __i) { _M_i = __i; }
 
       operator __integral_type() const
       { return load(); }
@@ -399,7 +399,7 @@
     atomic_bool(const atomic_bool&) = delete;
     atomic_bool& operator=(const atomic_bool&) volatile = delete;
 
-    atomic_bool(bool __i) : _M_base(__i) { }
+    constexpr atomic_bool(bool __i) : _M_base(__i) { }
 
     bool
     operator=(bool __i)
Index: include/bits/atomic_2.h
===================================================================
--- include/bits/atomic_2.h	(revision 162241)
+++ include/bits/atomic_2.h	(working copy)
@@ -89,7 +89,7 @@
     atomic_address(const atomic_address&) = delete;
     atomic_address& operator=(const atomic_address&) volatile = delete;
 
-    atomic_address(void* __v) { _M_i = __v; }
+    constexpr atomic_address(void* __v) { _M_i = __v; }
 
     bool
     is_lock_free() const
@@ -233,7 +233,7 @@
       __atomic_base& operator=(const __atomic_base&) volatile = delete;
 
       // Requires __integral_type convertible to _M_base._M_i.
-      __atomic_base(__integral_type __i) { _M_i = __i; }
+      constexpr __atomic_base(__integral_type __i) { _M_i = __i; }
 
       operator __integral_type() const
       { return load(); }
@@ -399,7 +399,7 @@
     atomic_bool(const atomic_bool&) = delete;
     atomic_bool& operator=(const atomic_bool&) volatile = delete;
 
-    atomic_bool(bool __i) : _M_base(__i) { }
+    constexpr atomic_bool(bool __i) : _M_base(__i) { }
 
     bool
     operator=(bool __i)
Index: include/bits/random.h
===================================================================
--- include/bits/random.h	(revision 162241)
+++ include/bits/random.h	(working copy)
@@ -166,12 +166,12 @@
       typedef _UIntType result_type;
 
       /** The multiplier. */
-      static const result_type multiplier   = __a;
+      static constexpr result_type multiplier   = __a;
       /** An increment. */
-      static const result_type increment    = __c;
+      static constexpr result_type increment    = __c;
       /** The modulus. */
-      static const result_type modulus      = __m;
-      static const result_type default_seed = 1u;
+      static constexpr result_type modulus      = __m;
+      static constexpr result_type default_seed = 1u;
 
       /**
        * @brief Constructs a %linear_congruential_engine random number
@@ -225,8 +225,8 @@
        *
        * @todo This should be constexpr.
        */
-      result_type
-      min() const
+      static constexpr result_type
+      min()
       { return __c == 0u ? 1u : 0u; }
 
       /**
@@ -234,8 +234,8 @@
        *
        * @todo This should be constexpr.
        */
-      result_type
-      max() const
+      static constexpr result_type
+      max()
       { return __m - 1u; }
 
       /**
@@ -399,20 +399,20 @@
       typedef _UIntType result_type;
 
       // parameter values
-      static const size_t      word_size                 = __w;
-      static const size_t      state_size                = __n;
-      static const size_t      shift_size                = __m;
-      static const size_t      mask_bits                 = __r;
-      static const result_type xor_mask                  = __a;
-      static const size_t      tempering_u               = __u;
-      static const result_type tempering_d               = __d;
-      static const size_t      tempering_s               = __s;
-      static const result_type tempering_b               = __b;
-      static const size_t      tempering_t               = __t;
-      static const result_type tempering_c               = __c;
-      static const size_t      tempering_l               = __l;
-      static const result_type initialization_multiplier = __f;
-      static const result_type default_seed = 5489u;
+      static constexpr size_t      word_size                 = __w;
+      static constexpr size_t      state_size                = __n;
+      static constexpr size_t      shift_size                = __m;
+      static constexpr size_t      mask_bits                 = __r;
+      static constexpr result_type xor_mask                  = __a;
+      static constexpr size_t      tempering_u               = __u;
+      static constexpr result_type tempering_d               = __d;
+      static constexpr size_t      tempering_s               = __s;
+      static constexpr result_type tempering_b               = __b;
+      static constexpr size_t      tempering_t               = __t;
+      static constexpr result_type tempering_c               = __c;
+      static constexpr size_t      tempering_l               = __l;
+      static constexpr result_type initialization_multiplier = __f;
+      static constexpr result_type default_seed = 5489u;
 
       // constructors and member function
       explicit
@@ -444,8 +444,8 @@
        *
        * @todo This should be constexpr.
        */
-      result_type
-      min() const
+      static constexpr result_type
+      min()
       { return 0; };
 
       /**
@@ -453,8 +453,8 @@
        *
        * @todo This should be constexpr.
        */
-      result_type
-      max() const
+      static constexpr result_type
+      max()
       { return __detail::_Shift<_UIntType, __w>::__value - 1; }
 
       /**
@@ -605,10 +605,10 @@
       typedef _UIntType result_type;
 
       // parameter values
-      static const size_t      word_size    = __w;
-      static const size_t      short_lag    = __s;
-      static const size_t      long_lag     = __r;
-      static const result_type default_seed = 19780503u;
+      static constexpr size_t      word_size    = __w;
+      static constexpr size_t      short_lag    = __s;
+      static constexpr size_t      long_lag     = __r;
+      static constexpr result_type default_seed = 19780503u;
 
       /**
        * @brief Constructs an explicitly seeded % subtract_with_carry_engine
@@ -660,8 +660,8 @@
        *
        * @todo This should be constexpr.
        */
-      result_type
-      min() const
+      static constexpr result_type
+      min()
       { return 0; }
 
       /**
@@ -670,8 +670,8 @@
        *
        * @todo This should be constexpr.
        */
-      result_type
-      max() const
+      static constexpr result_type
+      max()
       { return __detail::_Shift<_UIntType, __w>::__value - 1; }
 
       /**
@@ -791,8 +791,8 @@
       typedef typename _RandomNumberEngine::result_type result_type;
 
       // parameter values
-      static const size_t block_size = __p;
-      static const size_t used_block = __r;
+      static constexpr size_t block_size = __p;
+      static constexpr size_t used_block = __r;
 
       /**
        * @brief Constructs a default %discard_block_engine engine.
@@ -894,8 +894,8 @@
        *
        * @todo This should be constexpr.
        */
-      result_type
-      min() const
+      static constexpr result_type
+      min()
       { return _M_b.min(); }
 
       /**
@@ -903,8 +903,8 @@
        *
        * @todo This should be constexpr.
        */
-      result_type
-      max() const
+      static constexpr result_type
+      max()
       { return _M_b.max(); }
 
       /**
@@ -1109,8 +1109,8 @@
        *
        * @todo This should be constexpr.
        */
-      result_type
-      min() const
+      static constexpr result_type
+      min()
       { return 0U; }
 
       /**
@@ -1118,8 +1118,8 @@
        *
        * @todo This should be constexpr.
        */
-      result_type
-      max() const
+      static constexpr result_type
+      max()
       { return __detail::_Shift<_UIntType, __w>::__value - 1; }
 
       /**
@@ -1240,7 +1240,7 @@
       /** The type of the generated random value. */
       typedef typename _RandomNumberEngine::result_type result_type;
 
-      static const size_t table_size = __k;
+      static constexpr size_t table_size = __k;
 
       /**
        * @brief Constructs a default %shuffle_order_engine engine.
@@ -1345,8 +1345,8 @@
        *
        * @todo This should be constexpr.
        */
-      result_type
-      min() const
+      static constexpr result_type
+      min()
       { return _M_b.min(); }
 
       /**
@@ -1354,8 +1354,8 @@
        *
        * @todo This should be constexpr.
        */
-      result_type
-      max() const
+      static constexpr result_type
+      max()
       { return _M_b.max(); }
 
       /**
@@ -1567,12 +1567,12 @@
 
 #endif
 
-    result_type
-    min() const
+    static constexpr result_type
+    min()
     { return std::numeric_limits<result_type>::min(); }
 
-    result_type
-    max() const
+    static constexpr result_type
+    max()
     { return std::numeric_limits<result_type>::max(); }
 
     double
@@ -1614,7 +1614,7 @@
    */
 
   /**
-   * @addtogroup random_distributions_uniform Uniform
+   * @addtogroup random_distributions_uniform Uniform Distributions
    * @ingroup random_distributions
    * @{
    */
@@ -1972,7 +1972,7 @@
   /* @} */ // group random_distributions_uniform
 
   /**
-   * @addtogroup random_distributions_normal Normal
+   * @addtogroup random_distributions_normal Normal Distributions
    * @ingroup random_distributions
    * @{
    */
@@ -3226,7 +3226,7 @@
   /* @} */ // group random_distributions_normal
 
   /**
-   * @addtogroup random_distributions_bernoulli Bernoulli
+   * @addtogroup random_distributions_bernoulli Bernoulli Distributions
    * @ingroup random_distributions
    * @{
    */
@@ -3957,7 +3957,7 @@
   /* @} */ // group random_distributions_bernoulli
 
   /**
-   * @addtogroup random_distributions_poisson Poisson
+   * @addtogroup random_distributions_poisson Poisson Distributions
    * @ingroup random_distributions
    * @{
    */