From 9af5541e88764e639b2f6bc5d02b8d3f168bd1cd Mon Sep 17 00:00:00 2001
From: Paul Romano <paul.k.romano@gmail.com>
Date: Mon, 26 Oct 2020 17:00:26 -0500
Subject: [PATCH] Make Source::sample() method const

---
 docs/source/usersguide/settings.rst                       | 4 ++--
 examples/custom_source/source_ring.cpp                    | 2 +-
 .../parameterized_source_ring.cpp                         | 2 +-
 include/openmc/source.h                                   | 8 ++++----
 src/source.cpp                                            | 4 ++--
 tests/regression_tests/source_dlopen/source_sampling.cpp  | 2 +-
 .../parameterized_source_sampling.cpp                     | 2 +-
 7 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/docs/source/usersguide/settings.rst b/docs/source/usersguide/settings.rst
index 1d1403874..df22328e3 100644
--- a/docs/source/usersguide/settings.rst
+++ b/docs/source/usersguide/settings.rst
@@ -196,7 +196,7 @@ below.
 
   class CustomSource : public openmc::Source
   {
-    openmc::Particle::Bank sample(uint64_t* seed)
+    openmc::Particle::Bank sample(uint64_t* seed) const
     {
       openmc::Particle::Bank particle;
       // weight
@@ -271,7 +271,7 @@ the source class when it is created:
     CustomSource(double energy) : energy_{energy} { }
 
     // Samples from an instance of this class.
-    openmc::Particle::Bank sample(uint64_t* seed)
+    openmc::Particle::Bank sample(uint64_t* seed) const
     {
       openmc::Particle::Bank particle;
       // weight
diff --git a/examples/custom_source/source_ring.cpp b/examples/custom_source/source_ring.cpp
index 7ff3b03b4..a752216dc 100644
--- a/examples/custom_source/source_ring.cpp
+++ b/examples/custom_source/source_ring.cpp
@@ -7,7 +7,7 @@
 
 class RingSource : public openmc::Source
 {
-  openmc::Particle::Bank sample(uint64_t* seed)
+  openmc::Particle::Bank sample(uint64_t* seed) const
   {
     openmc::Particle::Bank particle;
     // wgt
diff --git a/examples/parameterized_custom_source/parameterized_source_ring.cpp b/examples/parameterized_custom_source/parameterized_source_ring.cpp
index 2176a073a..9f913dfee 100644
--- a/examples/parameterized_custom_source/parameterized_source_ring.cpp
+++ b/examples/parameterized_custom_source/parameterized_source_ring.cpp
@@ -31,7 +31,7 @@ class RingSource : public openmc::Source {
     }
 
     // Samples from an instance of this class.
-    openmc::Particle::Bank sample(uint64_t* seed)
+    openmc::Particle::Bank sample(uint64_t* seed) const
     {
       openmc::Particle::Bank particle;
       // wgt
diff --git a/include/openmc/source.h b/include/openmc/source.h
index 93e6bcf54..12e815699 100644
--- a/include/openmc/source.h
+++ b/include/openmc/source.h
@@ -36,7 +36,7 @@ public:
   virtual ~Source() = default;
 
   // Methods that must be implemented
-  virtual Particle::Bank sample(uint64_t* seed) = 0;
+  virtual Particle::Bank sample(uint64_t* seed) const = 0;
 
   // Methods that can be overridden
   virtual double strength() const { return 1.0; }
@@ -55,7 +55,7 @@ public:
   //! Sample from the external source distribution
   //! \param[inout] seed Pseudorandom seed pointer
   //! \return Sampled site
-  Particle::Bank sample(uint64_t* seed) override;
+  Particle::Bank sample(uint64_t* seed) const override;
 
   // Properties
   Particle::Type particle_type() const { return particle_; }
@@ -84,7 +84,7 @@ public:
   explicit FileSource(std::string path);
 
   // Methods
-  Particle::Bank sample(uint64_t* seed) override;
+  Particle::Bank sample(uint64_t* seed) const override;
 
 private:
   std::vector<Particle::Bank> sites_; //!< Source sites from a file
@@ -101,7 +101,7 @@ public:
   ~CustomSourceWrapper();
 
   // Defer implementation to custom source library
-  Particle::Bank sample(uint64_t* seed) override
+  Particle::Bank sample(uint64_t* seed) const override
   {
     return custom_source_->sample(seed);
   }
diff --git a/src/source.cpp b/src/source.cpp
index a7bb80747..ff8303147 100644
--- a/src/source.cpp
+++ b/src/source.cpp
@@ -141,7 +141,7 @@ IndependentSource::IndependentSource(pugi::xml_node node)
   }
 }
 
-Particle::Bank IndependentSource::sample(uint64_t* seed)
+Particle::Bank IndependentSource::sample(uint64_t* seed) const
 {
   Particle::Bank site;
 
@@ -261,7 +261,7 @@ FileSource::FileSource(std::string path)
   file_close(file_id);
 }
 
-Particle::Bank FileSource::sample(uint64_t* seed)
+Particle::Bank FileSource::sample(uint64_t* seed) const
 {
   size_t i_site = sites_.size()*prn(seed);
   return sites_[i_site];
diff --git a/tests/regression_tests/source_dlopen/source_sampling.cpp b/tests/regression_tests/source_dlopen/source_sampling.cpp
index 796b504f3..8eaf6265c 100644
--- a/tests/regression_tests/source_dlopen/source_sampling.cpp
+++ b/tests/regression_tests/source_dlopen/source_sampling.cpp
@@ -7,7 +7,7 @@
 
 class CustomSource : public openmc::Source
 {
-  openmc::Particle::Bank sample(uint64_t *seed)
+  openmc::Particle::Bank sample(uint64_t *seed) const
   {
     openmc::Particle::Bank particle;
     // wgt
diff --git a/tests/regression_tests/source_parameterized_dlopen/parameterized_source_sampling.cpp b/tests/regression_tests/source_parameterized_dlopen/parameterized_source_sampling.cpp
index 91c165dbc..da7d70e37 100644
--- a/tests/regression_tests/source_parameterized_dlopen/parameterized_source_sampling.cpp
+++ b/tests/regression_tests/source_parameterized_dlopen/parameterized_source_sampling.cpp
@@ -6,7 +6,7 @@ class CustomSource : public openmc::Source {
     CustomSource(double energy) : energy_(energy) { }
 
     // Samples from an instance of this class.
-    openmc::Particle::Bank sample(uint64_t* seed)
+    openmc::Particle::Bank sample(uint64_t* seed) const
     {
       openmc::Particle::Bank particle;
       // wgt