Use concepts on BarycentreCalculator and drop the specializations #3919

eggrobin · 2024-03-28T03:23:42Z

Keep an optimization for the subtraction of 0 conditioned on concepts.

Compilation error:

Before

`BarycentreCalculator<Mass, Position<World>> b1;`

1>barycentre_calculator_test.cpp
1>C:\Users\robin\Projects\mockingbirdnest\Principia\quantities\named_quantities.hpp(18,44): error C2679: binary '*': no operator found which takes a right-hand operand of type 'Scalar' (or there is no acceptable conversion)
1>C:\Users\robin\Projects\mockingbirdnest\Principia\quantities\named_quantities.hpp(18,44): error C2679:         with
1>C:\Users\robin\Projects\mockingbirdnest\Principia\quantities\named_quantities.hpp(18,44): error C2679:         [
1>C:\Users\robin\Projects\mockingbirdnest\Principia\quantities\named_quantities.hpp(18,44): error C2679:             Scalar=principia::geometry::_point::internal::Point<principia::geometry::_grassmann::internal::Multivector<principia::quantities::_quantities::internal::Length,principia::geometry::_frame::internal::Frame<principia::geometry::WorldTag,principia::geometry::_frame::internal::Arbitrary,principia::geometry::_frame::internal::Handedness::Right,nullptr>,1>>
1>C:\Users\robin\Projects\mockingbirdnest\Principia\quantities\named_quantities.hpp(18,44): error C2679:         ]
1>(compiling source file 'barycentre_calculator_test.cpp')
1>C:\Users\robin\Projects\mockingbirdnest\Principia\quantities\quantities.hpp(66,22):
1>could be

[A long list of operator*s]

1>C:\Users\robin\Projects\mockingbirdnest\Principia\quantities\named_quantities.hpp(18,44):
1>while trying to match the argument list '(principia::quantities::_quantities::internal::Mass, Scalar)'
1>        with
1>        [
1>            Scalar=principia::geometry::_point::internal::Point<principia::geometry::_grassmann::internal::Multivector<principia::quantities::_quantities::internal::Length,principia::geometry::_frame::internal::Frame<principia::geometry::WorldTag,principia::geometry::_frame::internal::Arbitrary,principia::geometry::_frame::internal::Handedness::Right,nullptr>,1>>
1>        ]
1>C:\Users\robin\Projects\mockingbirdnest\Principia\quantities\named_quantities.hpp(18,44):
1>the template instantiation context (the oldest one first) is
1>	C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator_test.cpp(48,47):
1>	see reference to class template instantiation 'principia::geometry::_barycentre_calculator::internal::BarycentreCalculator<principia::quantities::_quantities::internal::Mass,principia::geometry::_point::internal::Point<principia::geometry::_grassmann::internal::Multivector<principia::quantities::_quantities::internal::Length,principia::geometry::_frame::internal::Frame<principia::geometry::WorldTag,principia::geometry::_frame::internal::Arbitrary,principia::geometry::_frame::internal::Handedness::Right,nullptr>,1>>>' being compiled
1>	C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator.hpp(29,3):
1>	see reference to alias template instantiation 'principia::quantities::_named_quantities::internal::Product<Vector,Scalar>' being compiled
1>        with
1>        [
1>            Vector=principia::quantities::_quantities::internal::Mass,
1>            Scalar=principia::geometry::_point::internal::Point<principia::geometry::_grassmann::internal::Multivector<principia::quantities::_quantities::internal::Length,principia::geometry::_frame::internal::Frame<principia::geometry::WorldTag,principia::geometry::_frame::internal::Arbitrary,principia::geometry::_frame::internal::Handedness::Right,nullptr>,1>>
1>        ]
1>Done building project "geometry.vcxproj" -- FAILED.

`BarycentreCalculator<Mass, Velocity<World>> b2;`

  b2.Add(1 * Kilogram, World::unmoving);
  b2.Get();

This one fails only in Get():

1>barycentre_calculator_test.cpp
1>C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator_body.hpp(31,31): error C2676: binary '/': 'const principia::geometry::_grassmann::internal::Multivector<principia::quantities::_quantities::internal::Quantity<principia::quantities::_dimensions::internal::Dimensions<1,1,-1,0,0,0,0,0>>,principia::geometry::_frame::internal::Frame<principia::geometry::WorldTag,principia::geometry::_frame::internal::Arbitrary,principia::geometry::_frame::internal::Handedness::Right,nullptr>,1>' does not define this operator or a conversion to a type acceptable to the predefined operator
1>(compiling source file 'barycentre_calculator_test.cpp')
1>C:\Users\robin\Projects\mockingbirdnest\Principia\quantities\quantities.hpp(112,1):
1>could be

[A long list of operator/s]

1>C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator_body.hpp(31,31):
1>the template instantiation context (the oldest one first) is
1>	C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator_test.cpp(48,47):
1>	see reference to class template instantiation 'principia::geometry::_barycentre_calculator::internal::BarycentreCalculator<principia::quantities::_quantities::internal::Mass,principia::geometry::_grassmann::internal::Multivector<principia::quantities::_named_quantities::internal::Speed,principia::geometry::_frame::internal::Frame<principia::geometry::WorldTag,principia::geometry::_frame::internal::Arbitrary,principia::geometry::_frame::internal::Handedness::Right,nullptr>,1>>' being compiled
1>	C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator_body.hpp(29,58):
1>	while compiling class template member function 'Vector principia::geometry::_barycentre_calculator::internal::BarycentreCalculator<Vector,principia::geometry::_grassmann::internal::Multivector<principia::quantities::_named_quantities::internal::Speed,principia::geometry::_frame::internal::Frame<principia::geometry::WorldTag,principia::geometry::_frame::internal::Arbitrary,principia::geometry::_frame::internal::Handedness::Right,nullptr>,1>>::Get(void) const'
1>        with
1>        [
1>            Vector=principia::quantities::_quantities::internal::Mass
1>        ]
1>		C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator_test.cpp(50,9):
1>		see the first reference to 'principia::geometry::_barycentre_calculator::internal::BarycentreCalculator<principia::quantities::_quantities::internal::Mass,principia::geometry::_grassmann::internal::Multivector<principia::quantities::_named_quantities::internal::Speed,principia::geometry::_frame::internal::Frame<principia::geometry::WorldTag,principia::geometry::_frame::internal::Arbitrary,principia::geometry::_frame::internal::Handedness::Right,nullptr>,1>>::Get' in 'principia::geometry::BarycentreCalculatorDeathTest_Error_Test::TestBody'
1>Done building project "geometry.vcxproj" -- FAILED.

After

`BarycentreCalculator<Mass, Position<World>> b1;`

1>barycentre_calculator_test.cpp
1>C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator_test.cpp(48,3): error C7602: 'principia::geometry::_barycentre_calculator::internal::BarycentreCalculator': the associated constraints are not satisfied
1>C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator.hpp(20,1):
1>see declaration of 'principia::geometry::_barycentre_calculator::internal::BarycentreCalculator'
1>C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator.hpp(18,24):
1>the concept 'principia::quantities::_concepts::internal::homogeneous_field<principia::geometry::_point::internal::Point<principia::geometry::_grassmann::internal::Multivector<principia::quantities::_quantities::internal::Length,principia::geometry::_frame::internal::Frame<principia::geometry::WorldTag,principia::geometry::_frame::internal::Arbitrary,principia::geometry::_frame::internal::Handedness::Right,nullptr>,1>>>' evaluated to false
1>	C:\Users\robin\Projects\mockingbirdnest\Principia\quantities\concepts.hpp(87,29):
1>	the concept 'principia::quantities::_concepts::internal::homogeneous_ring<principia::geometry::_point::internal::Point<principia::geometry::_grassmann::internal::Multivector<principia::quantities::_quantities::internal::Length,principia::geometry::_frame::internal::Frame<principia::geometry::WorldTag,principia::geometry::_frame::internal::Arbitrary,principia::geometry::_frame::internal::Handedness::Right,nullptr>,1>>>' evaluated to false
1>		C:\Users\robin\Projects\mockingbirdnest\Principia\quantities\concepts.hpp(47,5):
1>		the concept 'principia::quantities::_concepts::internal::additive_group<principia::geometry::_point::internal::Point<principia::geometry::_grassmann::internal::Multivector<principia::quantities::_quantities::internal::Length,principia::geometry::_frame::internal::Frame<principia::geometry::WorldTag,principia::geometry::_frame::internal::Arbitrary,principia::geometry::_frame::internal::Handedness::Right,nullptr>,1>>>' evaluated to false
1>			C:\Users\robin\Projects\mockingbirdnest\Principia\quantities\concepts.hpp(21,5):
1>			unary '+': 'principia::geometry::_point::internal::Point<principia::geometry::_grassmann::internal::Multivector<principia::quantities::_quantities::internal::Length,principia::geometry::_frame::internal::Frame<principia::geometry::WorldTag,principia::geometry::_frame::internal::Arbitrary,principia::geometry::_frame::internal::Handedness::Right,nullptr>,1>>' does not define this operator or a conversion to a type acceptable to the predefined operator
1>			C:\Users\robin\Projects\mockingbirdnest\Principia\quantities\concepts.hpp(21,5):
1>			'+': illegal for class
1>C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator_test.cpp(48,47): error C2641: cannot deduce template arguments for 'principia::geometry::_barycentre_calculator::internal::BarycentreCalculator'
1>C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator_test.cpp(48,47): error C2783: 'principia::geometry::_barycentre_calculator::internal::BarycentreCalculator<Point,Weight> principia::geometry::_barycentre_calculator::internal::BarycentreCalculator(void)': could not deduce template argument for 'Point'
1>C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator.hpp(22,3):
1>see declaration of 'principia::geometry::_barycentre_calculator::internal::BarycentreCalculator'
1>C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator_test.cpp(48,47): error C2783: 'principia::geometry::_barycentre_calculator::internal::BarycentreCalculator<Point,Weight> principia::geometry::_barycentre_calculator::internal::BarycentreCalculator(void)': could not deduce template argument for 'Weight'
1>C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator.hpp(22,3):
1>see declaration of 'principia::geometry::_barycentre_calculator::internal::BarycentreCalculator'
1>C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator_test.cpp(48,47): error C2780: 'principia::geometry::_barycentre_calculator::internal::BarycentreCalculator<Point,Weight> principia::geometry::_barycentre_calculator::internal::BarycentreCalculator(principia::geometry::_barycentre_calculator::internal::BarycentreCalculator<Point,Weight>)': expects 1 arguments - 0 provided
1>C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator.hpp(20,1):
1>see declaration of 'principia::geometry::_barycentre_calculator::internal::BarycentreCalculator'
1>Done building project "geometry.vcxproj" -- FAILED.

`BarycentreCalculator<Mass, Velocity<World>> b2;`

1>barycentre_calculator_test.cpp
1>C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator_test.cpp(48,3): error C7602: 'principia::geometry::_barycentre_calculator::internal::BarycentreCalculator': the associated constraints are not satisfied
1>C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator.hpp(20,1):
1>see declaration of 'principia::geometry::_barycentre_calculator::internal::BarycentreCalculator'
1>C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator.hpp(18,24):
1>the concept 'principia::quantities::_concepts::internal::homogeneous_field<principia::geometry::_grassmann::internal::Multivector<principia::quantities::_named_quantities::internal::Speed,principia::geometry::_frame::internal::Frame<principia::geometry::WorldTag,principia::geometry::_frame::internal::Arbitrary,principia::geometry::_frame::internal::Handedness::Right,nullptr>,1>>' evaluated to false
1>	C:\Users\robin\Projects\mockingbirdnest\Principia\quantities\concepts.hpp(87,29):
1>	the concept 'principia::quantities::_concepts::internal::homogeneous_ring<principia::geometry::_grassmann::internal::Multivector<principia::quantities::_named_quantities::internal::Speed,principia::geometry::_frame::internal::Frame<principia::geometry::WorldTag,principia::geometry::_frame::internal::Arbitrary,principia::geometry::_frame::internal::Handedness::Right,nullptr>,1>>' evaluated to false
1>		C:\Users\robin\Projects\mockingbirdnest\Principia\quantities\concepts.hpp(49,11):
1>		binary '*': 'principia::geometry::_grassmann::internal::Multivector<principia::quantities::_named_quantities::internal::Speed,principia::geometry::_frame::internal::Frame<principia::geometry::WorldTag,principia::geometry::_frame::internal::Arbitrary,principia::geometry::_frame::internal::Handedness::Right,nullptr>,1>' does not define this operator or a conversion to a type acceptable to the predefined operator
1>			C:\Users\robin\Projects\mockingbirdnest\Principia\quantities\quantities.hpp(109,1):
1>			could be

[A long list of operator*s]

1>C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator_test.cpp(48,47): error C2641: cannot deduce template arguments for 'principia::geometry::_barycentre_calculator::internal::BarycentreCalculator'
1>C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator_test.cpp(48,47): error C2783: 'principia::geometry::_barycentre_calculator::internal::BarycentreCalculator<Point,Weight> principia::geometry::_barycentre_calculator::internal::BarycentreCalculator(void)': could not deduce template argument for 'Point'
1>C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator.hpp(22,3):
1>see declaration of 'principia::geometry::_barycentre_calculator::internal::BarycentreCalculator'
1>C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator_test.cpp(48,47): error C2783: 'principia::geometry::_barycentre_calculator::internal::BarycentreCalculator<Point,Weight> principia::geometry::_barycentre_calculator::internal::BarycentreCalculator(void)': could not deduce template argument for 'Weight'
1>C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator.hpp(22,3):
1>see declaration of 'principia::geometry::_barycentre_calculator::internal::BarycentreCalculator'
1>C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator_test.cpp(48,47): error C2780: 'principia::geometry::_barycentre_calculator::internal::BarycentreCalculator<Point,Weight> principia::geometry::_barycentre_calculator::internal::BarycentreCalculator(principia::geometry::_barycentre_calculator::internal::BarycentreCalculator<Point,Weight>)': expects 1 arguments - 0 provided
1>C:\Users\robin\Projects\mockingbirdnest\Principia\geometry\barycentre_calculator.hpp(20,1):
1>see declaration of 'principia::geometry::_barycentre_calculator::internal::BarycentreCalculator'
1>Done building project "geometry.vcxproj" -- FAILED.

pleroy · 2024-03-28T08:03:36Z

geometry/barycentre_calculator_body.hpp

@@ -52,8 +71,7 @@ T Barycentre(Container<T> const& ts, Container<Scalar> const& weights) {
  BarycentreCalculator<T, Scalar> calculator;
  auto ts_it = ts.begin();
  auto weights_it = weights.begin();
-  for (;


Let's keep the old formatting, one line for stanza of the loop header.

pleroy · 2024-03-28T08:04:55Z

geometry/pair.hpp

@@ -108,6 +108,9 @@ using enable_if_vector_t = typename enable_if_vector<T, U>::type;
 template<typename T1, typename T2>
 class Pair final {
 public:
+  Pair()
+    requires std::default_initializable<T1> && std::default_initializable<T2> =
+      default;


Would this fit at the end of the previous line?

eggrobin added 7 commits March 27, 2024 00:59

Constraints on BarycentreCalculator

a78f733

can we get rid of specializations?

260b3a3

Merge branch 'dof' into concept-barycentre

0bb6c53

accidentally removed a definition

78e2578

seems to work

9c2075c

clean up friends

9284c51

Merge remote-tracking branch 'la-vache/master' into concept-barycentre

ae7ccc1

pleroy reviewed Mar 28, 2024

View reviewed changes

pleroy added the LGTM label Mar 28, 2024

eggrobin added 5 commits March 28, 2024 11:42

formatting

a8a16dc

no vector spaces over int

c58a5a0

More ints

a6a1991

more ints

5a8e786

another one

f3a6763

eggrobin merged commit ca43086 into mockingbirdnest:master Mar 28, 2024
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Use concepts on BarycentreCalculator and drop the specializations #3919

Use concepts on BarycentreCalculator and drop the specializations #3919

eggrobin commented Mar 28, 2024

pleroy Mar 28, 2024

pleroy Mar 28, 2024

eggrobin Mar 28, 2024

Use concepts on BarycentreCalculator and drop the specializations #3919

Use concepts on BarycentreCalculator and drop the specializations #3919

Conversation

eggrobin commented Mar 28, 2024

Before

BarycentreCalculator<Mass, Position<World>> b1;

BarycentreCalculator<Mass, Velocity<World>> b2;

After

BarycentreCalculator<Mass, Position<World>> b1;

BarycentreCalculator<Mass, Velocity<World>> b2;

pleroy Mar 28, 2024

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pleroy Mar 28, 2024

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eggrobin Mar 28, 2024

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`BarycentreCalculator<Mass, Position<World>> b1;`

`BarycentreCalculator<Mass, Velocity<World>> b2;`

`BarycentreCalculator<Mass, Position<World>> b1;`

`BarycentreCalculator<Mass, Velocity<World>> b2;`