fixed snippets
diff --git a/doc/snippets/Slicing_arrayexpr.cpp b/doc/snippets/Slicing_arrayexpr.cpp
index 2df8180..6d09980 100644
--- a/doc/snippets/Slicing_arrayexpr.cpp
+++ b/doc/snippets/Slicing_arrayexpr.cpp
@@ -1,4 +1,4 @@
 ArrayXi ind(5); ind<<4,2,5,5,3;
 MatrixXi A = MatrixXi::Random(4,6);
 cout << "Initial matrix A:\n" << A << "\n\n";
-cout << "A(all,ind-1):\n" << A(all,ind-1) << "\n\n";
+cout << "A(all,ind-1):\n" << A(Eigen::placeholders::all,ind-1) << "\n\n";
diff --git a/doc/snippets/Slicing_rawarray_cxx11.cpp b/doc/snippets/Slicing_rawarray_cxx11.cpp
index 478550f..7a3e6e5 100644
--- a/doc/snippets/Slicing_rawarray_cxx11.cpp
+++ b/doc/snippets/Slicing_rawarray_cxx11.cpp
@@ -1,3 +1,3 @@
 MatrixXi A = MatrixXi::Random(4,6);
 cout << "Initial matrix A:\n" << A << "\n\n";
-cout << "A(all,{4,2,5,5,3}):\n" << A(all,{4,2,5,5,3}) << "\n\n";
+cout << "A(all,{4,2,5,5,3}):\n" << A(Eigen::placeholders::all,{4,2,5,5,3}) << "\n\n";
diff --git a/doc/snippets/Slicing_stdvector_cxx11.cpp b/doc/snippets/Slicing_stdvector_cxx11.cpp
index 555f662..74f0727 100644
--- a/doc/snippets/Slicing_stdvector_cxx11.cpp
+++ b/doc/snippets/Slicing_stdvector_cxx11.cpp
@@ -1,4 +1,4 @@
 std::vector<int> ind{4,2,5,5,3};
 MatrixXi A = MatrixXi::Random(4,6);
 cout << "Initial matrix A:\n" << A << "\n\n";
-cout << "A(all,ind):\n" << A(all,ind) << "\n\n";
+cout << "A(all,ind):\n" << A(Eigen::placeholders::all,ind) << "\n\n";