Minor fixes

Change-Id: I4c825bbd19b2d902d17dce37d228e23a808c87fb

docs/source/nnls_modeling.rst

diff --git a/docs/source/nnls_modeling.rst b/docs/source/nnls_modeling.rst
index 832e292..6ec14bf 100644
--- a/docs/source/nnls_modeling.rst
+++ b/docs/source/nnls_modeling.rst
@@ -82,7 +82,7 @@
      public:
       virtual bool Evaluate(double const* const* parameters,
                             double* residuals,
-                            double** jacobians) = 0;
+                            double** jacobians) const = 0;
       const vector<int32>& parameter_block_sizes();
       int num_residuals() const;
 
@@ -100,7 +100,7 @@
 the corresponding accessors. This information will be verified by the
 :class:`Problem` when added with :func:`Problem::AddResidualBlock`.
 
-.. function:: bool CostFunction::Evaluate(double const* const* parameters, double* residuals, double** jacobians)
+.. function:: bool CostFunction::Evaluate(double const* const* parameters, double* residuals, double** jacobians) const
 
    Compute the residual vector and the Jacobian matrices.
 

internal/ceres/ceres_cuda_kernels.h

diff --git a/internal/ceres/ceres_cuda_kernels.h b/internal/ceres/ceres_cuda_kernels.h
index 989399f..f033147 100644
--- a/internal/ceres/ceres_cuda_kernels.h
+++ b/internal/ceres/ceres_cuda_kernels.h
@@ -61,6 +61,7 @@
 // Compute x = x + double(y). Input array is float (FP32), output array is
 // double (FP64). Both arrays must already be on GPU memory.
 void CudaDsxpy(double* x, float* y, const int size, cudaStream_t stream);
-}  // namespace ceres_cuda_kernels
 
-#endif  // CERES_NO_CUDA
\ No newline at end of file
+}  // namespace ceres::internal
+
+#endif  // CERES_NO_CUDA

internal/ceres/dense_cholesky_test.cc

diff --git a/internal/ceres/dense_cholesky_test.cc b/internal/ceres/dense_cholesky_test.cc
index e513641..5f96939 100644
--- a/internal/ceres/dense_cholesky_test.cc
+++ b/internal/ceres/dense_cholesky_test.cc
@@ -32,6 +32,7 @@
 
 #include <memory>
 #include <numeric>
+#include <sstream>
 #include <string>
 #include <vector>