RcppCore · eddelbuettel · Jul 9, 2026 · Jul 9, 2026 · Jul 9, 2026 · Jul 9, 2026
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
@@ -30,6 +30,11 @@ jobs:
       - name: Setup
         uses: eddelbuettel/github-actions/r-ci@master
 
+      - name: Setup ccache for R
+        uses: eddelbuettel/github-actions/ccache-with-R@master
+        with:
+          key: ${{ matrix.name }}-${{ matrix.openmp }}
+
       - name: Configure
         run: ./configure; cat src/Makevars
 

diff --git a/ChangeLog b/ChangeLog
@@ -1,3 +1,14 @@
+2026-07-09  Dirk Eddelbuettel  <edd@debian.org>
+
+	* DESCRIPTION (Version, Date): RcppArmadillo 15.4.1-1
+        * inst/NEWS.Rd: Idem
+        * configure.ac: Idem
+        * configure: Idem
+
+	* inst/include/armadillo_bits/: Armadillo 15.4.1
+
+	* .github/workflows/ci.yaml: Enable ccache in matrix
+
 2026-06-18  Dirk Eddelbuettel  <edd@debian.org>
 
 	* DESCRIPTION (Version, Date): RcppArmadillo 15.4.0-1

diff --git a/DESCRIPTION b/DESCRIPTION
@@ -1,8 +1,8 @@
 Package: RcppArmadillo
 Type: Package
 Title: 'Rcpp' Integration for the 'Armadillo' Templated Linear Algebra Library
-Version: 15.4.0-1
-Date: 2026-06-17
+Version: 15.4.1-1
+Date: 2026-07-09
 Authors@R: c(person("Dirk", "Eddelbuettel", role = c("aut", "cre"), email = "edd@debian.org",
                     comment = c(ORCID = "0000-0001-6419-907X")),
              person("Romain", "Francois", role = "aut",

diff --git a/configure b/configure
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.72 for RcppArmadillo 15.4.0-1.
+# Generated by GNU Autoconf 2.72 for RcppArmadillo 15.4.1-1.
 #
 # Report bugs to <edd@debian.org>.
 #
@@ -603,8 +603,8 @@ MAKEFLAGS=
 # Identity of this package.
 PACKAGE_NAME='RcppArmadillo'
 PACKAGE_TARNAME='rcpparmadillo'
-PACKAGE_VERSION='15.4.0-1'
-PACKAGE_STRING='RcppArmadillo 15.4.0-1'
+PACKAGE_VERSION='15.4.1-1'
+PACKAGE_STRING='RcppArmadillo 15.4.1-1'
 PACKAGE_BUGREPORT='edd@debian.org'
 PACKAGE_URL=''
 
@@ -1223,7 +1223,7 @@ if test "$ac_init_help" = "long"; then
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-'configure' configures RcppArmadillo 15.4.0-1 to adapt to many kinds of systems.
+'configure' configures RcppArmadillo 15.4.1-1 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1285,7 +1285,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of RcppArmadillo 15.4.0-1:";;
+     short | recursive ) echo "Configuration of RcppArmadillo 15.4.1-1:";;
    esac
   cat <<\_ACEOF
 
@@ -1366,7 +1366,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-RcppArmadillo configure 15.4.0-1
+RcppArmadillo configure 15.4.1-1
 generated by GNU Autoconf 2.72
 
 Copyright (C) 2023 Free Software Foundation, Inc.
@@ -1482,7 +1482,7 @@ cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by RcppArmadillo $as_me 15.4.0-1, which was
+It was created by RcppArmadillo $as_me 15.4.1-1, which was
 generated by GNU Autoconf 2.72.  Invocation command line was
 
   $ $0$ac_configure_args_raw
@@ -3946,7 +3946,7 @@ cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by RcppArmadillo $as_me 15.4.0-1, which was
+This file was extended by RcppArmadillo $as_me 15.4.1-1, which was
 generated by GNU Autoconf 2.72.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -4001,7 +4001,7 @@ ac_cs_config_escaped=`printf "%s\n" "$ac_cs_config" | sed "s/^ //; s/'/'\\\\\\\\
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config='$ac_cs_config_escaped'
 ac_cs_version="\\
-RcppArmadillo config.status 15.4.0-1
+RcppArmadillo config.status 15.4.1-1
 configured by $0, generated by GNU Autoconf 2.72,
   with options \\"\$ac_cs_config\\"
 

diff --git a/configure.ac b/configure.ac
@@ -11,7 +11,7 @@
 AC_PREREQ([2.69])
 
 ## Process this file with autoconf to produce a configure script.
-AC_INIT([RcppArmadillo],[15.4.0-1],[edd@debian.org])
+AC_INIT([RcppArmadillo],[15.4.1-1],[edd@debian.org])
 
 ## Set R_HOME, respecting an environment variable if one is set
 : ${R_HOME=$(R RHOME)}

diff --git a/inst/NEWS.Rd b/inst/NEWS.Rd
@@ -3,6 +3,16 @@
 \newcommand{\ghpr}{\href{https://github.com/RcppCore/RcppArmadillo/pull/#1}{##1}}
 \newcommand{\ghit}{\href{https://github.com/RcppCore/RcppArmadillo/issues/#1}{##1}}
 
+\section{Changes in RcppArmadillo version 15.4.1-1 [github-only] (2026-07-09)}{
+  \itemize{
+    \item Upgraded to Armadillo release 15.4.1 (Medium Roast Agave)
+    \itemize{
+      \item Fix for rare infinite recursion bug in sparse version of \code{diagmat()}
+      \item More efficient checks for aliasing
+    }
+  }
+}
+
 \section{Changes in RcppArmadillo version 15.4.0-1 (2026-06-17)}{
   \itemize{
     \item Upgraded to Armadillo release 15.4.0 (Medium Roast Agave)

diff --git a/inst/include/armadillo_bits/Mat_bones.hpp b/inst/include/armadillo_bits/Mat_bones.hpp
@@ -938,6 +938,12 @@ class Mat<eT>::fixed : public Mat<eT>
   arma_warn_unused arma_inline       eT* memptr();
   arma_warn_unused arma_inline const eT* memptr() const;
 
+  arma_inline       subview_row<eT> row(const uword row_num);
+  arma_inline const subview_row<eT> row(const uword row_num) const;
+
+  arma_inline       subview_col<eT> col(const uword col_num);
+  arma_inline const subview_col<eT> col(const uword col_num) const;
+
   arma_warn_unused arma_inline bool is_vec() const;
 
   inline const Mat<eT>& fill(const eT val);

diff --git a/inst/include/armadillo_bits/Mat_meat.hpp b/inst/include/armadillo_bits/Mat_meat.hpp
@@ -10746,6 +10746,66 @@ Mat<eT>::fixed<fixed_n_rows, fixed_n_cols>::memptr() const
 
 
 
+template<typename eT>
+template<uword fixed_n_rows, uword fixed_n_cols>
+arma_inline
+subview_row<eT>
+Mat<eT>::fixed<fixed_n_rows, fixed_n_cols>::row(const uword row_num)
+  {
+  arma_debug_sigprint();
+
+  arma_conform_check_bounds( row_num >= fixed_n_rows, "Mat::row(): index out of bounds" );
+
+  return subview_row<eT>(*this, row_num);
+  }
+
+
+
+template<typename eT>
+template<uword fixed_n_rows, uword fixed_n_cols>
+arma_inline
+const subview_row<eT>
+Mat<eT>::fixed<fixed_n_rows, fixed_n_cols>::row(const uword row_num) const
+  {
+  arma_debug_sigprint();
+
+  arma_conform_check_bounds( row_num >= fixed_n_rows, "Mat::row(): index out of bounds" );
+
+  return subview_row<eT>(*this, row_num);
+  }
+
+
+
+template<typename eT>
+template<uword fixed_n_rows, uword fixed_n_cols>
+arma_inline
+subview_col<eT>
+Mat<eT>::fixed<fixed_n_rows, fixed_n_cols>::col(const uword col_num)
+  {
+  arma_debug_sigprint();
+
+  arma_conform_check_bounds( col_num >= fixed_n_cols, "Mat::col(): index out of bounds" );
+
+  return subview_col<eT>(*this, col_num);
+  }
+
+
+
+template<typename eT>
+template<uword fixed_n_rows, uword fixed_n_cols>
+arma_inline
+const subview_col<eT>
+Mat<eT>::fixed<fixed_n_rows, fixed_n_cols>::col(const uword col_num) const
+  {
+  arma_debug_sigprint();
+
+  arma_conform_check_bounds( col_num >= fixed_n_cols, "Mat::col(): index out of bounds" );
+
+  return subview_col<eT>(*this, col_num);
+  }
+
+
+
 template<typename eT>
 template<uword fixed_n_rows, uword fixed_n_cols>
 arma_inline

diff --git a/inst/include/armadillo_bits/SpBase_bones.hpp b/inst/include/armadillo_bits/SpBase_bones.hpp
@@ -52,8 +52,6 @@ struct SpBase
   {
   arma_inline const derived& get_ref() const;
 
-  arma_inline bool is_alias(const SpMat<elem_type>& X) const;
-
   arma_warn_unused inline const SpOp<derived,spop_htrans>  t() const;  //!< Hermitian transpose
   arma_warn_unused inline const SpOp<derived,spop_htrans> ht() const;  //!< Hermitian transpose
   arma_warn_unused inline const SpOp<derived,spop_strans> st() const;  //!< simple transpose

diff --git a/inst/include/armadillo_bits/SpBase_meat.hpp b/inst/include/armadillo_bits/SpBase_meat.hpp
@@ -31,16 +31,6 @@ SpBase<elem_type,derived>::get_ref() const
 
 
 
-template<typename elem_type, typename derived>
-arma_inline
-bool
-SpBase<elem_type,derived>::is_alias(const SpMat<elem_type>& X) const
-  {
-  return (*this).get_ref().is_alias(X);
-  }
-
-
-
 template<typename elem_type, typename derived>
 inline
 const SpOp<derived, spop_htrans>

diff --git a/inst/include/armadillo_bits/SpGlue_bones.hpp b/inst/include/armadillo_bits/SpGlue_bones.hpp
@@ -37,7 +37,8 @@ struct SpGlue : public SpBase< typename T1::elem_type, SpGlue<T1, T2, spglue_typ
   inline  SpGlue(const T1& in_A, const T2& in_B, const elem_type in_aux);
   inline ~SpGlue();
 
-  arma_inline bool is_alias(const SpMat<elem_type>& X) const;
+  template<typename eT2>
+  arma_inline bool is_alias(const SpMat<eT2>& X) const;
 
   const T1&       A;    //!< first operand;  must be derived from SpBase
   const T2&       B;    //!< second operand; must be derived from SpBase

diff --git a/inst/include/armadillo_bits/SpGlue_meat.hpp b/inst/include/armadillo_bits/SpGlue_meat.hpp
@@ -54,9 +54,10 @@ SpGlue<T1,T2,spglue_type>::~SpGlue()
 
 
 template<typename T1, typename T2, typename spglue_type>
+template<typename eT2>
 arma_inline
 bool
-SpGlue<T1,T2,spglue_type>::is_alias(const SpMat<typename T1::elem_type>& X) const
+SpGlue<T1,T2,spglue_type>::is_alias(const SpMat<eT2>& X) const
   {
   return (A.is_alias(X) || B.is_alias(X));
   }

diff --git a/inst/include/armadillo_bits/SpMat_bones.hpp b/inst/include/armadillo_bits/SpMat_bones.hpp
@@ -649,7 +649,8 @@ class SpMat : public SpBase< eT, SpMat<eT> >
   template<typename eT2, typename T1, typename Functor> inline void init_xform_mt(const SpBase<eT2,T1>& x, const Functor& func);
 
   //! don't use this unless you're writing internal Armadillo code
-  arma_inline bool is_alias(const SpMat<eT>& X) const;
+  template<typename eT2>
+  arma_inline bool is_alias(const SpMat<eT2>& X) const;
 
 
   protected:

diff --git a/inst/include/armadillo_bits/SpMat_meat.hpp b/inst/include/armadillo_bits/SpMat_meat.hpp
@@ -6015,11 +6015,14 @@ SpMat<eT>::init_xform_mt(const SpBase<eT2,T1>& A, const Functor& func)
 
 
 template<typename eT>
+template<typename eT2>
 arma_inline
 bool
-SpMat<eT>::is_alias(const SpMat<eT>& X) const
+SpMat<eT>::is_alias(const SpMat<eT2>& X) const
   {
-  return (&X == this);
+  arma_debug_sigprint();
+
+  return (is_same_type<eT,eT2>::yes) && (void_ptr(this) == void_ptr(&X));
   }
 
 

diff --git a/inst/include/armadillo_bits/SpOp_bones.hpp b/inst/include/armadillo_bits/SpOp_bones.hpp
@@ -38,7 +38,8 @@ struct SpOp : public SpBase< typename T1::elem_type, SpOp<T1, op_type> >
   inline          SpOp(const T1& in_m, const uword     in_aux_uword_a, const uword in_aux_uword_b);
   inline         ~SpOp();
 
-  arma_inline bool is_alias(const SpMat<elem_type>& X) const;
+  template<typename eT2>
+  arma_inline bool is_alias(const SpMat<eT2>& X) const;
 
   const T1&       m;            //!< the operand; must be derived from SpBase
         elem_type aux;          //!< auxiliary data, using the element type as used by T1

diff --git a/inst/include/armadillo_bits/SpOp_meat.hpp b/inst/include/armadillo_bits/SpOp_meat.hpp
@@ -64,9 +64,10 @@ SpOp<T1, op_type>::~SpOp()
 
 
 template<typename T1, typename op_type>
+template<typename eT2>
 arma_inline
 bool
-SpOp<T1, op_type>::is_alias(const SpMat<typename T1::elem_type>& X) const
+SpOp<T1, op_type>::is_alias(const SpMat<eT2>& X) const
   {
   return m.is_alias(X);
   }

diff --git a/inst/include/armadillo_bits/SpSubview_bones.hpp b/inst/include/armadillo_bits/SpSubview_bones.hpp
@@ -323,7 +323,8 @@ class SpSubview : public SpBase< eT, SpSubview<eT> >
   inline const_row_iterator end_row(const uword row_num) const;
 
   //! don't use this unless you're writing internal Armadillo code
-  arma_inline bool is_alias(const SpMat<eT>& X) const;
+  template<typename eT2>
+  arma_inline bool is_alias(const SpMat<eT2>& X) const;
 
 
   private:

diff --git a/inst/include/armadillo_bits/SpSubview_col_list_bones.hpp b/inst/include/armadillo_bits/SpSubview_col_list_bones.hpp
@@ -89,6 +89,8 @@ class SpSubview_col_list : public SpBase< eT, SpSubview_col_list<eT,T1> >
   inline static void schur_inplace(SpMat<eT>& out, const SpSubview_col_list& in);
   inline static void   div_inplace(SpMat<eT>& out, const SpSubview_col_list& in);
 
+  template<typename eT2>
+  arma_inline bool is_alias(const SpMat<eT2>& X) const;
 
   friend class SpMat<eT>;
   };

diff --git a/inst/include/armadillo_bits/SpSubview_col_list_meat.hpp b/inst/include/armadillo_bits/SpSubview_col_list_meat.hpp
@@ -714,4 +714,15 @@ SpSubview_col_list<eT,T1>::div_inplace(SpMat<eT>& out, const SpSubview_col_list&
 
 
 
+template<typename eT, typename T1>
+template<typename eT2>
+arma_inline
+bool
+SpSubview_col_list<eT,T1>::is_alias(const SpMat<eT2>& X) const
+  {
+  return m.is_alias(X);
+  }
+
+
+
 //! @}
diff --git a/inst/include/armadillo_bits/SpSubview_meat.hpp b/inst/include/armadillo_bits/SpSubview_meat.hpp
@@ -1786,9 +1786,10 @@ SpSubview<eT>::end_row(const uword row_num) const
 
 
 template<typename eT>
+template<typename eT2>
 arma_inline
 bool
-SpSubview<eT>::is_alias(const SpMat<eT>& X) const
+SpSubview<eT>::is_alias(const SpMat<eT2>& X) const
   {
   return m.is_alias(X);
   }

diff --git a/inst/include/armadillo_bits/arma_version.hpp b/inst/include/armadillo_bits/arma_version.hpp
@@ -23,7 +23,7 @@
 
 #define ARMA_VERSION_MAJOR 15
 #define ARMA_VERSION_MINOR 4
-#define ARMA_VERSION_PATCH 0
+#define ARMA_VERSION_PATCH 1
 #define ARMA_VERSION_NAME  "Medium Roast Agave"
 
 

diff --git a/inst/include/armadillo_bits/diskio_meat.hpp b/inst/include/armadillo_bits/diskio_meat.hpp
@@ -1865,7 +1865,7 @@ diskio::load_csv_ascii(Mat<eT>& x, std::istream& f, std::string& err_msg, const
 
   try { x.zeros(f_n_rows, f_n_cols); } catch(...) { err_msg = "not enough memory"; return false; }
 
-  if(strict)  { x.fill(Datum<eT>::nan); }   // take into account that each row may have a unique number of columns
+  if(strict && is_real<eT>::yes)  { x.fill(Datum<eT>::nan); }   // take into account that each row may have a unique number of columns
 
   const bool use_mp = (arma_config::openmp) && (f_n_rows >= 2) && (f_n_cols >= 64);