Re: [PATCH] PR libstdc++/85749 constrain seed sequences for random number engines

2018-05-15 Thread Jonathan Wakely 

On 15/05/18 16:36 +0100, Jonathan Wakely wrote:

Constrain constructors and member functions of random number engines so
that functions taking seed sequences can only be called with types that
meet the seed sequence requirements.

PR libstdc++/85749
* include/bits/random.h (__detail::__is_seed_seq): New SFINAE helper.
(linear_congruential_engine, mersenne_twister_engine)
(subtract_with_carry_engine, discard_block_engine)
(independent_bits_engine, shuffle_order_engine): Use __is_seed_seq to
constrain function templates taking seed sequences.
* include/bits/random.tcc (linear_congruential_engine::seed(_Sseq&))
(mersenne_twister_engine::seed(_Sseq&))
(subtract_with_carry_engine::seed(_Sseq&)): Change return types to
match declarations.
* include/ext/random (simd_fast_mersenne_twister_engine): Use
__is_seed_seq to constrain function templates taking seed sequences.
* include/ext/random.tcc (simd_fast_mersenne_twister_engine::seed):
Change return type to match declaration.
* testsuite/26_numerics/random/discard_block_engine/cons/seed_seq2.cc:
New.
* testsuite/26_numerics/random/independent_bits_engine/cons/
seed_seq2.cc: New.
* testsuite/26_numerics/random/linear_congruential_engine/cons/
seed_seq2.cc: New.
* testsuite/26_numerics/random/mersenne_twister_engine/cons/
seed_seq2.cc: New.
* testsuite/26_numerics/random/pr60037-neg.cc: Adjust dg-error lineno.
* testsuite/26_numerics/random/shuffle_order_engine/cons/seed_seq2.cc:
New.
* testsuite/26_numerics/random/subtract_with_carry_engine/cons/
seed_seq2.cc: New.
* testsuite/ext/random/simd_fast_mersenne_twister_engine/cons/
seed_seq2.cc: New.

Tested powerpc64le-linux, committed to trunk.





commit 2197343e0cb9439687e453f37bf9ea2908bd499d
Author: Jonathan Wakely 
Date:   Sat May 12 00:22:23 2018 +0100

   PR libstdc++/85749 constrain seed sequences for random number engines
   
   Constrain constructors and member functions of random number engines so

   that functions taking seed sequences can only be called with types that
   meet the seed sequence requirements.
   
   PR libstdc++/85749

   * include/bits/random.h (__detail::__is_seed_seq): New SFINAE helper.
   (linear_congruential_engine, mersenne_twister_engine)
   (subtract_with_carry_engine, discard_block_engine)
   (independent_bits_engine, shuffle_order_engine): Use __is_seed_seq to
   constrain function templates taking seed sequences.
   * include/bits/random.tcc (linear_congruential_engine::seed(_Sseq&))
   (mersenne_twister_engine::seed(_Sseq&))
   (subtract_with_carry_engine::seed(_Sseq&)): Change return types to
   match declarations.
   * include/ext/random (simd_fast_mersenne_twister_engine): Use
   __is_seed_seq to constrain function templates taking seed sequences.
   * include/ext/random.tcc (simd_fast_mersenne_twister_engine::seed):
   Change return type to match declaration.
   * 
testsuite/26_numerics/random/discard_block_engine/cons/seed_seq2.cc:
   New.
   * testsuite/26_numerics/random/independent_bits_engine/cons/
   seed_seq2.cc: New.
   * testsuite/26_numerics/random/linear_congruential_engine/cons/
   seed_seq2.cc: New.
   * testsuite/26_numerics/random/mersenne_twister_engine/cons/
   seed_seq2.cc: New.
   * testsuite/26_numerics/random/pr60037-neg.cc: Adjust dg-error 
lineno.
   * 
testsuite/26_numerics/random/shuffle_order_engine/cons/seed_seq2.cc:
   New.
   * testsuite/26_numerics/random/subtract_with_carry_engine/cons/
   seed_seq2.cc: New.
   * testsuite/ext/random/simd_fast_mersenne_twister_engine/cons/
   seed_seq2.cc: New.

diff --git a/libstdc++-v3/include/bits/random.h 
b/libstdc++-v3/include/bits/random.h
index f812bbf18b1..b76cfbb558e 100644
--- a/libstdc++-v3/include/bits/random.h
+++ b/libstdc++-v3/include/bits/random.h
@@ -185,6 +185,21 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
_Engine& _M_g;
  };

+template
+  using __seed_seq_generate_t = decltype(
+ std::declval<_Sseq&>().generate(std::declval(),
+ std::declval()));
+
+// Detect whether _Sseq is a valid seed sequence for
+// a random number engine _Engine with result type _Res.
+template>
+  using __is_seed_seq = __and_<
+__not_, _Engine>>,
+   is_unsigned,
+   __not_>
+  >;
+
  } // namespace __detail


I'm considering backporting this, with a simpler constraint:

   // Detect whether _Sseq is a valid seed sequence for
   // a random number

[PATCH] PR libstdc++/85749 constrain seed sequences for random number engines

2018-05-15 Thread Jonathan Wakely 

Constrain constructors and member functions of random number engines so
that functions taking seed sequences can only be called with types that
meet the seed sequence requirements.

PR libstdc++/85749
* include/bits/random.h (__detail::__is_seed_seq): New SFINAE helper.
(linear_congruential_engine, mersenne_twister_engine)
(subtract_with_carry_engine, discard_block_engine)
(independent_bits_engine, shuffle_order_engine): Use __is_seed_seq to
constrain function templates taking seed sequences.
* include/bits/random.tcc (linear_congruential_engine::seed(_Sseq&))
(mersenne_twister_engine::seed(_Sseq&))
(subtract_with_carry_engine::seed(_Sseq&)): Change return types to
match declarations.
* include/ext/random (simd_fast_mersenne_twister_engine): Use
__is_seed_seq to constrain function templates taking seed sequences.
* include/ext/random.tcc (simd_fast_mersenne_twister_engine::seed):
Change return type to match declaration.
* testsuite/26_numerics/random/discard_block_engine/cons/seed_seq2.cc:
New.
* testsuite/26_numerics/random/independent_bits_engine/cons/
seed_seq2.cc: New.
* testsuite/26_numerics/random/linear_congruential_engine/cons/
seed_seq2.cc: New.
* testsuite/26_numerics/random/mersenne_twister_engine/cons/
seed_seq2.cc: New.
* testsuite/26_numerics/random/pr60037-neg.cc: Adjust dg-error lineno.
* testsuite/26_numerics/random/shuffle_order_engine/cons/seed_seq2.cc:
New.
* testsuite/26_numerics/random/subtract_with_carry_engine/cons/
seed_seq2.cc: New.
* testsuite/ext/random/simd_fast_mersenne_twister_engine/cons/
seed_seq2.cc: New.

Tested powerpc64le-linux, committed to trunk.


commit 2197343e0cb9439687e453f37bf9ea2908bd499d
Author: Jonathan Wakely 
Date:   Sat May 12 00:22:23 2018 +0100

PR libstdc++/85749 constrain seed sequences for random number engines

Constrain constructors and member functions of random number engines so
that functions taking seed sequences can only be called with types that
meet the seed sequence requirements.

PR libstdc++/85749
* include/bits/random.h (__detail::__is_seed_seq): New SFINAE helper.
(linear_congruential_engine, mersenne_twister_engine)
(subtract_with_carry_engine, discard_block_engine)
(independent_bits_engine, shuffle_order_engine): Use __is_seed_seq to
constrain function templates taking seed sequences.
* include/bits/random.tcc (linear_congruential_engine::seed(_Sseq&))
(mersenne_twister_engine::seed(_Sseq&))
(subtract_with_carry_engine::seed(_Sseq&)): Change return types to
match declarations.
* include/ext/random (simd_fast_mersenne_twister_engine): Use
__is_seed_seq to constrain function templates taking seed sequences.
* include/ext/random.tcc (simd_fast_mersenne_twister_engine::seed):
Change return type to match declaration.
* testsuite/26_numerics/random/discard_block_engine/cons/seed_seq2.cc:
New.
* testsuite/26_numerics/random/independent_bits_engine/cons/
seed_seq2.cc: New.
* testsuite/26_numerics/random/linear_congruential_engine/cons/
seed_seq2.cc: New.
* testsuite/26_numerics/random/mersenne_twister_engine/cons/
seed_seq2.cc: New.
* testsuite/26_numerics/random/pr60037-neg.cc: Adjust dg-error lineno.
* testsuite/26_numerics/random/shuffle_order_engine/cons/seed_seq2.cc:
New.
* testsuite/26_numerics/random/subtract_with_carry_engine/cons/
seed_seq2.cc: New.
* testsuite/ext/random/simd_fast_mersenne_twister_engine/cons/
seed_seq2.cc: New.

diff --git a/libstdc++-v3/include/bits/random.h b/libstdc++-v3/include/bits/random.h
index f812bbf18b1..b76cfbb558e 100644
--- a/libstdc++-v3/include/bits/random.h
+++ b/libstdc++-v3/include/bits/random.h
@@ -185,6 +185,21 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	_Engine& _M_g;
   };
 
+template
+  using __seed_seq_generate_t = decltype(
+	  std::declval<_Sseq&>().generate(std::declval(),
+	  std::declval()));
+
+// Detect whether _Sseq is a valid seed sequence for
+// a random number engine _Engine with result type _Res.
+template>
+  using __is_seed_seq = __and_<
+__not_, _Engine>>,
+	is_unsigned,
+	__not_>
+  >;
+
   } // namespace __detail
 
   /**
@@ -233,6 +248,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   static_assert(__m == 0u || (__a < __m && __c < __m),
 		"template argument substituting __m out of bounds");
 
+  template
+	using _If_seed_seq