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Fix ambiguous sqrt() overload caused by ADL

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Here's the compiler error:
```
/home/tav/git/Sleipnir/build/_deps/eigen3-src/Eigen/src/Householder/Householder.h:82:16: error: call of overloaded ‘sqrt(boost::decimal::decimal64_t)’ is ambiguous
   82 |     beta = sqrt(numext::abs2(c0) + tailSqNorm);
      |            ~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/home/tav/git/Sleipnir/build/_deps/eigen3-src/Eigen/src/Householder/Householder.h:82:16: note: there are 2 candidates
In file included from /home/tav/git/Sleipnir/build/_deps/eigen3-src/Eigen/Core:198,
                 from /home/tav/git/Sleipnir/test/src/optimization/cart_pole_problem_test.cpp:8:
/home/tav/git/Sleipnir/build/_deps/eigen3-src/Eigen/src/Core/MathFunctions.h:1384:75: note: candidate 1: ‘typename Eigen::internal::sqrt_retval<typename Eigen::internal::global_math_functions_filtering_base<Scalar>::type>::type Eigen::numext::sqrt(const Scalar&) [with Scalar = boost::decimal::decimal64_t; typename Eigen::internal::sqrt_retval<typename Eigen::internal::global_math_functions_filtering_base<Scalar>::type>::type = boost::decimal::decimal64_t; typename Eigen::internal::global_math_functions_filtering_base<Scalar>::type = boost::decimal::decimal64_t]’
 1384 | EIGEN_DEVICE_FUNC EIGEN_ALWAYS_INLINE EIGEN_MATHFUNC_RETVAL(sqrt, Scalar) sqrt(const Scalar& x) {
      |                                                                           ^~~~
In file included from /home/tav/git/Sleipnir/build/_deps/decimal-src/include/boost/decimal/detail/cmath/ellint_1.hpp:16,
                 from /home/tav/git/Sleipnir/build/_deps/decimal-src/include/boost/decimal/cmath.hpp:18,
                 from /home/tav/git/Sleipnir/build/_deps/decimal-src/include/boost/decimal.hpp:33,
                 from /home/tav/git/Sleipnir/test/include/scalar_types_under_test.hpp:6,
                 from /home/tav/git/Sleipnir/test/src/optimization/cart_pole_problem_test.cpp:19:
/home/tav/git/Sleipnir/build/_deps/decimal-src/include/boost/decimal/detail/cmath/sqrt.hpp:167:16: note: candidate 2: ‘constexpr T boost::decimal::sqrt(T) requires  is_decimal_floating_point_v<T> [with T = decimal64_t]’
  167 | constexpr auto sqrt(const T val) noexcept
      |                ^~~~
```

Calling a function via its unqualified name invokes argument-dependent lookup. In this case, since `using numext::sqrt;` was used, both `numext::sqrt()` and `boost::decimal::sqrt()` participated in overload resolution. Since only `numext::sqrt()` was intended, the fix is to call that overload directly instead.

See merge request libeigen/eigen!2044

(cherry picked from commit be56fff1ff)
This commit is contained in:
Tyler Veness
2025-10-26 02:03:22 +00:00
committed by Antonio Sanchez
parent da889c88f9
commit a9110bfc87
1 changed files with 1 additions and 2 deletions
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3
Eigen/src/Householder/Householder.h
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@@ -65,7 +65,6 @@ template <typename EssentialPart>
EIGEN_DEVICE_FUNC void MatrixBase<Derived>::makeHouseholder(EssentialPart& essential, Scalar& tau,
RealScalar& beta) const {
using numext::conj;
using numext::sqrt;
EIGEN_STATIC_ASSERT_VECTOR_ONLY(EssentialPart)
VectorBlock<const Derived, EssentialPart::SizeAtCompileTime> tail(derived(), 1, size() - 1);
@@ -79,7 +78,7 @@ EIGEN_DEVICE_FUNC void MatrixBase<Derived>::makeHouseholder(EssentialPart& essen
beta = numext::real(c0);
essential.setZero();
} else {
beta = sqrt(numext::abs2(c0) + tailSqNorm);
beta = numext::sqrt(numext::abs2(c0) + tailSqNorm);
if (numext::real(c0) >= RealScalar(0)) beta = -beta;
essential = tail / (c0 - beta);
tau = conj((beta - c0) / beta);