From fae6c68442e742e81188058d4f6323104d71beba Mon Sep 17 00:00:00 2001
From: Daniele Rapetti <5535617+Iximiel@users.noreply.github.com>
Date: Thu, 16 Jan 2025 11:11:50 +0100
Subject: [PATCH 1/5] Now cregex "appears" to be included (for backward
 compatibility)

---
 src/config/Config.inc.in           | 6 +-----
 src/maketools/update-config-txt.sh | 2 ++
 2 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/src/config/Config.inc.in b/src/config/Config.inc.in
index 39ff6f0989..82e96761bc 100644
--- a/src/config/Config.inc.in
+++ b/src/config/Config.inc.in
@@ -154,13 +154,9 @@ bool hasDlopen() {
   return false;
 #endif
 }
-
+/// This will always return true for backward compatibility
 bool hasCregex() {
-#ifdef __PLUMED_HAS_CREGEX
   return true;
-#else
-  return false;
-#endif
 }
 
 bool hasMolfile() {
diff --git a/src/maketools/update-config-txt.sh b/src/maketools/update-config-txt.sh
index 198750e188..a55a863a60 100755
--- a/src/maketools/update-config-txt.sh
+++ b/src/maketools/update-config-txt.sh
@@ -132,6 +132,8 @@ echo "# if option xx is on then plumed has beeen compiled with -D__PLUMED_HAS_XX
       echo "has $u off"
     fi
   done
+  #this is here for backward compatibility (since we are using c++17 that has <regex>)
+  echo "has cregex on"
 } | sort
 echo
 echo "# other defines"

From 28f719428d811a04404429a60fa715f04d8a160a Mon Sep 17 00:00:00 2001
From: Daniele Rapetti <5535617+Iximiel@users.noreply.github.com>
Date: Thu, 16 Jan 2025 11:25:28 +0100
Subject: [PATCH 2/5] with constexpr

---
 src/config/Config.h      | 3 ++-
 src/config/Config.inc.in | 4 ----
 2 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/src/config/Config.h b/src/config/Config.h
index 1604c5bab6..0db2785f26 100644
--- a/src/config/Config.h
+++ b/src/config/Config.h
@@ -99,7 +99,8 @@ bool hasDlopen();
 
 bool isInstalled();
 
-bool hasCregex();
+/// This will always return true for backward compatibility
+constexpr bool hasCregex(){return true;}
 
 bool hasMolfile();
 
diff --git a/src/config/Config.inc.in b/src/config/Config.inc.in
index 82e96761bc..cb821b217e 100644
--- a/src/config/Config.inc.in
+++ b/src/config/Config.inc.in
@@ -154,10 +154,6 @@ bool hasDlopen() {
   return false;
 #endif
 }
-/// This will always return true for backward compatibility
-bool hasCregex() {
-  return true;
-}
 
 bool hasMolfile() {
 #ifdef __PLUMED_HAS_MOLFILE_PLUGINS

From 272e2cb88ac6a4c2141fc24742a714860b3586c8 Mon Sep 17 00:00:00 2001
From: Daniele Rapetti <5535617+Iximiel@users.noreply.github.com>
Date: Thu, 16 Jan 2025 11:34:07 +0100
Subject: [PATCH 3/5] added a test for "config has cregex" backward
 compatibility

---
 regtest/basic/rt-cregex-backward-compatibility/Makefile      | 1 +
 regtest/basic/rt-cregex-backward-compatibility/config        | 3 +++
 regtest/basic/rt-cregex-backward-compatibility/out.reference | 1 +
 3 files changed, 5 insertions(+)
 create mode 100644 regtest/basic/rt-cregex-backward-compatibility/Makefile
 create mode 100644 regtest/basic/rt-cregex-backward-compatibility/config
 create mode 100644 regtest/basic/rt-cregex-backward-compatibility/out.reference

diff --git a/regtest/basic/rt-cregex-backward-compatibility/Makefile b/regtest/basic/rt-cregex-backward-compatibility/Makefile
new file mode 100644
index 0000000000..3703b27cea
--- /dev/null
+++ b/regtest/basic/rt-cregex-backward-compatibility/Makefile
@@ -0,0 +1 @@
+include ../../scripts/test.make
diff --git a/regtest/basic/rt-cregex-backward-compatibility/config b/regtest/basic/rt-cregex-backward-compatibility/config
new file mode 100644
index 0000000000..6db62fcce2
--- /dev/null
+++ b/regtest/basic/rt-cregex-backward-compatibility/config
@@ -0,0 +1,3 @@
+type=plumed
+#this just tests that config will always return cregex as existing, for backward compatibility
+arg="config has cregex"
diff --git a/regtest/basic/rt-cregex-backward-compatibility/out.reference b/regtest/basic/rt-cregex-backward-compatibility/out.reference
new file mode 100644
index 0000000000..092a566f04
--- /dev/null
+++ b/regtest/basic/rt-cregex-backward-compatibility/out.reference
@@ -0,0 +1 @@
+cregex on

From cc37cedbb8076abc73b70e888db63a58fabf2f36 Mon Sep 17 00:00:00 2001
From: Daniele Rapetti <5535617+Iximiel@users.noreply.github.com>
Date: Thu, 16 Jan 2025 11:42:02 +0100
Subject: [PATCH 4/5] removing the old `plumed_needs="cregex"` from the regtest
 requirements

---
 regtest/isdb/rt-Metainference-averaging/config             | 1 -
 regtest/isdb/rt-jcoupling-string-type/config               | 1 -
 regtest/isdb/rt-metainference-mc-chunksize/config          | 1 -
 regtest/isdb/rt-metainference-optisigmamean-sem-max/config | 1 -
 regtest/isdb/rt-metainference-optisigmamean-sem/config     | 1 -
 regtest/isdb/rt-metainference-regres-zero/config           | 1 -
 regtest/isdb/rt-metainferencebase-averaging/config         | 1 -
 regtest/isdb/rt-metainferencebase-regres-zero/config       | 1 -
 regtest/isdb/rt-metainferencebase-sem-max/config           | 1 -
 9 files changed, 9 deletions(-)

diff --git a/regtest/isdb/rt-Metainference-averaging/config b/regtest/isdb/rt-Metainference-averaging/config
index ecf9c90e84..bf6f932c83 100644
--- a/regtest/isdb/rt-Metainference-averaging/config
+++ b/regtest/isdb/rt-Metainference-averaging/config
@@ -1,4 +1,3 @@
-plumed_needs="cregex"
 type=driver
 # this is to test a different name
 arg="--plumed plumed.dat --trajectory-stride 2 --timestep 0.002 --mf_xtc trajectory.xtc --dump-forces atom_forces --dump-forces-fmt=%7.3f"
diff --git a/regtest/isdb/rt-jcoupling-string-type/config b/regtest/isdb/rt-jcoupling-string-type/config
index ecf9c90e84..bf6f932c83 100644
--- a/regtest/isdb/rt-jcoupling-string-type/config
+++ b/regtest/isdb/rt-jcoupling-string-type/config
@@ -1,4 +1,3 @@
-plumed_needs="cregex"
 type=driver
 # this is to test a different name
 arg="--plumed plumed.dat --trajectory-stride 2 --timestep 0.002 --mf_xtc trajectory.xtc --dump-forces atom_forces --dump-forces-fmt=%7.3f"
diff --git a/regtest/isdb/rt-metainference-mc-chunksize/config b/regtest/isdb/rt-metainference-mc-chunksize/config
index ecf9c90e84..bf6f932c83 100644
--- a/regtest/isdb/rt-metainference-mc-chunksize/config
+++ b/regtest/isdb/rt-metainference-mc-chunksize/config
@@ -1,4 +1,3 @@
-plumed_needs="cregex"
 type=driver
 # this is to test a different name
 arg="--plumed plumed.dat --trajectory-stride 2 --timestep 0.002 --mf_xtc trajectory.xtc --dump-forces atom_forces --dump-forces-fmt=%7.3f"
diff --git a/regtest/isdb/rt-metainference-optisigmamean-sem-max/config b/regtest/isdb/rt-metainference-optisigmamean-sem-max/config
index ecf9c90e84..bf6f932c83 100644
--- a/regtest/isdb/rt-metainference-optisigmamean-sem-max/config
+++ b/regtest/isdb/rt-metainference-optisigmamean-sem-max/config
@@ -1,4 +1,3 @@
-plumed_needs="cregex"
 type=driver
 # this is to test a different name
 arg="--plumed plumed.dat --trajectory-stride 2 --timestep 0.002 --mf_xtc trajectory.xtc --dump-forces atom_forces --dump-forces-fmt=%7.3f"
diff --git a/regtest/isdb/rt-metainference-optisigmamean-sem/config b/regtest/isdb/rt-metainference-optisigmamean-sem/config
index ecf9c90e84..bf6f932c83 100644
--- a/regtest/isdb/rt-metainference-optisigmamean-sem/config
+++ b/regtest/isdb/rt-metainference-optisigmamean-sem/config
@@ -1,4 +1,3 @@
-plumed_needs="cregex"
 type=driver
 # this is to test a different name
 arg="--plumed plumed.dat --trajectory-stride 2 --timestep 0.002 --mf_xtc trajectory.xtc --dump-forces atom_forces --dump-forces-fmt=%7.3f"
diff --git a/regtest/isdb/rt-metainference-regres-zero/config b/regtest/isdb/rt-metainference-regres-zero/config
index ecf9c90e84..bf6f932c83 100644
--- a/regtest/isdb/rt-metainference-regres-zero/config
+++ b/regtest/isdb/rt-metainference-regres-zero/config
@@ -1,4 +1,3 @@
-plumed_needs="cregex"
 type=driver
 # this is to test a different name
 arg="--plumed plumed.dat --trajectory-stride 2 --timestep 0.002 --mf_xtc trajectory.xtc --dump-forces atom_forces --dump-forces-fmt=%7.3f"
diff --git a/regtest/isdb/rt-metainferencebase-averaging/config b/regtest/isdb/rt-metainferencebase-averaging/config
index ecf9c90e84..bf6f932c83 100644
--- a/regtest/isdb/rt-metainferencebase-averaging/config
+++ b/regtest/isdb/rt-metainferencebase-averaging/config
@@ -1,4 +1,3 @@
-plumed_needs="cregex"
 type=driver
 # this is to test a different name
 arg="--plumed plumed.dat --trajectory-stride 2 --timestep 0.002 --mf_xtc trajectory.xtc --dump-forces atom_forces --dump-forces-fmt=%7.3f"
diff --git a/regtest/isdb/rt-metainferencebase-regres-zero/config b/regtest/isdb/rt-metainferencebase-regres-zero/config
index dec4ec0c0d..147b050b4a 100644
--- a/regtest/isdb/rt-metainferencebase-regres-zero/config
+++ b/regtest/isdb/rt-metainferencebase-regres-zero/config
@@ -1,4 +1,3 @@
-plumed_needs="cregex"
 type=driver
 
 arg="--plumed plumed.dat --trajectory-stride 2 --timestep 0.002 --mf_xtc trajectory.xtc --dump-forces atom_forces --dump-forces-fmt=%7.3f"
diff --git a/regtest/isdb/rt-metainferencebase-sem-max/config b/regtest/isdb/rt-metainferencebase-sem-max/config
index ecf9c90e84..bf6f932c83 100644
--- a/regtest/isdb/rt-metainferencebase-sem-max/config
+++ b/regtest/isdb/rt-metainferencebase-sem-max/config
@@ -1,4 +1,3 @@
-plumed_needs="cregex"
 type=driver
 # this is to test a different name
 arg="--plumed plumed.dat --trajectory-stride 2 --timestep 0.002 --mf_xtc trajectory.xtc --dump-forces atom_forces --dump-forces-fmt=%7.3f"

From 06c2cbd40d9bb56687a9c7717d424cd94866ef0c Mon Sep 17 00:00:00 2001
From: Daniele Rapetti <5535617+Iximiel@users.noreply.github.com>
Date: Thu, 16 Jan 2025 12:25:26 +0100
Subject: [PATCH 5/5] run astyle

---
 src/config/Config.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/config/Config.h b/src/config/Config.h
index 0db2785f26..4f225200b9 100644
--- a/src/config/Config.h
+++ b/src/config/Config.h
@@ -100,7 +100,7 @@ bool hasDlopen();
 bool isInstalled();
 
 /// This will always return true for backward compatibility
-constexpr bool hasCregex(){return true;}
+constexpr bool hasCregex() {return true;}
 
 bool hasMolfile();