Rename empty_traits to clear_mutations

In common C++ libraries, empty is an adjective, not a verb.

src/character.h

@@ -1449,8 +1449,8 @@ class Character : public Creature, public visitable<Character>
         const std::bitset<NUM_VISION_MODES> &get_vision_modes() const {
             return vision_mode_cache;
         }
-        /** Empties the trait list */
-        void empty_traits();
+        /** Empties the trait and mutations lists */
+        void clear_mutations();
         /**
          * Adds mandatory scenario and profession traits unless you already have them
          * And if you do already have them, refunds the points for the trait

src/newcharacter.cpp

@@ -2709,7 +2709,7 @@ std::vector<trait_id> Character::get_mutations( bool include_hidden ) const
     return result;
 }
 
-void Character::empty_traits()
+void Character::clear_mutations()
 {
     while( !my_traits.empty() ) {
         toggle_trait( *my_traits.begin() );
@@ -2916,7 +2916,7 @@ void reset_scenario( avatar &u, const scenario *scen )
             u.toggle_trait( t );
         }
     }
-    u.empty_traits();
+    u.clear_mutations();
     u.recalc_hp();
     u.empty_skills();
     u.add_traits();

src/npc.cpp

@@ -421,7 +421,7 @@ void npc::randomize( const npc_class_id &type )
     starting_clothes( *this, myclass, male );
     starting_inv( *this, myclass );
     has_new_items = true;
-    empty_traits();
+    clear_mutations();
 
     // Add fixed traits
     for( const auto &tid : trait_group::traits_from( myclass->traits ) ) {

src/player.cpp

@@ -290,7 +290,7 @@ player::player()
     next_expected_position = cata::nullopt;
     death_drops = true;
 
-    empty_traits();
+    clear_mutations();
 
     nv_cached = false;
     volume = 0;

tests/char_biometrics_test.cpp

@@ -57,7 +57,7 @@ static float bodyweight_kg_at_bmi( player &dummy, float bmi )
 // Clear player traits and give them a single trait by name
 static void set_single_trait( player &dummy, std::string trait_name )
 {
-    dummy.empty_traits();
+    dummy.clear_mutations();
     dummy.toggle_trait( trait_id( trait_name ) );
     REQUIRE( dummy.has_trait( trait_id( trait_name ) ) );
 }
@@ -363,7 +363,7 @@ TEST_CASE( "mutations may affect character metabolic rate", "[biometrics][metabo
     // Metabolic base rate uses PLAYER_HUNGER_RATE from game_balance.json, described as "base hunger
     // rate per 5 minutes". With no metabolism-affecting mutations, metabolism should be this value.
     const float normal_metabolic_rate = get_option<float>( "PLAYER_HUNGER_RATE" );
-    dummy.empty_traits();
+    dummy.clear_mutations();
     CHECK( dummy.metabolic_rate_base() == normal_metabolic_rate );
 
     // The remaining checks assume the configured base rate is 1.0; if this is ever changed in the

tests/char_healing_test.cpp

@@ -10,7 +10,7 @@
 static void give_one_trait( player &dummy, const std::string trait_name )
 {
     const trait_id trait( trait_name );
-    dummy.empty_traits();
+    dummy.clear_mutations();
     dummy.toggle_trait( trait );
     REQUIRE( dummy.has_trait( trait ) );
 }
@@ -29,7 +29,7 @@ TEST_CASE( "traits and mutations affecting healing rate", "[heal][trait][mutatio
     REQUIRE( dummy.get_healthy() == 0 );
 
     GIVEN( "no traits" ) {
-        dummy.empty_traits();
+        dummy.clear_mutations();
 
         THEN( "there are no healing modifiers from mutations" ) {
             CHECK( dummy.mutation_value( "healing_resting" ) == 0.0f );

tests/encumbrance_test.cpp

@@ -26,7 +26,7 @@ static void test_encumbrance_on(
 )
 {
     CAPTURE( body_part );
-    p.empty_traits();
+    p.clear_mutations();
     p.worn.clear();
     if( tweak_player ) {
         tweak_player( p );

tests/item_tname_test.cpp

@@ -47,7 +47,7 @@ static const skill_id skill_survival( "survival" );
 
 TEST_CASE( "food with hidden effects", "[item][tname][hidden]" )
 {
-    g->u.empty_traits();
+    g->u.clear_mutations();
 
     GIVEN( "food with hidden poison" ) {
         item coffee = item( "coffee_pod" );
@@ -386,7 +386,7 @@ TEST_CASE( "weapon fouling", "[item][tname][fouling][dirt]" )
         item gun( "hk_mp5" );
 
         // Ensure the player and gun are normal size to prevent "too big" or "too small" suffix in tname
-        g->u.empty_traits();
+        g->u.clear_mutations();
         REQUIRE( gun.get_sizing( g-> u, true ) == item::sizing::human_sized_human_char );
         REQUIRE_FALSE( gun.has_flag( "OVERSIZE" ) );
         REQUIRE_FALSE( gun.has_flag( "UNDERSIZE" ) );

tests/iteminfo_test.cpp

@@ -17,7 +17,7 @@
 static void test_info_equals( const item &i, const iteminfo_query &q,
                               const std::string &reference )
 {
-    g->u.empty_traits();
+    g->u.clear_mutations();
     std::vector<iteminfo> info_v;
     std::string info = i.info( info_v, &q, 1 );
     CHECK( info == reference );
@@ -26,7 +26,7 @@ static void test_info_equals( const item &i, const iteminfo_query &q,
 static void test_info_contains( const item &i, const iteminfo_query &q,
                                 const std::string &reference )
 {
-    g->u.empty_traits();
+    g->u.clear_mutations();
     std::vector<iteminfo> info_v;
     std::string info = i.info( info_v, &q, 1 );
     using Catch::Matchers::Contains;
@@ -515,7 +515,7 @@ TEST_CASE( "show available recipes with item as an ingredient", "[item][iteminfo
 {
     iteminfo_query q = q_vec( { iteminfo_parts::DESCRIPTION_APPLICABLE_RECIPES } );
     const recipe *purtab = &recipe_id( "pur_tablets" ).obj();
-    g->u.empty_traits();
+    g->u.clear_mutations();
 
     GIVEN( "character has a potassium iodide tablet and no skill" ) {
         item &iodine = g->u.i_add( item( "iodine" ) );

tests/itemname_test.cpp

@@ -11,7 +11,7 @@
 TEST_CASE( "item sizing display", "[item][iteminfo][display_name][sizing]" )
 {
     GIVEN( "player is a normal size" ) {
-        g->u.empty_traits();
+        g->u.clear_mutations();
 
         WHEN( "the item is a normal size" ) {
             std::string name = item( "bookplate" ).display_name();
@@ -46,7 +46,7 @@ TEST_CASE( "item sizing display", "[item][iteminfo][display_name][sizing]" )
     }
 
     GIVEN( "player is a huge size" ) {
-        g->u.empty_traits();
+        g->u.clear_mutations();
         g->u.toggle_trait( trait_id( "HUGE_OK" ) );
 
         WHEN( "the item is a normal size" ) {
@@ -82,7 +82,7 @@ TEST_CASE( "item sizing display", "[item][iteminfo][display_name][sizing]" )
     }
 
     GIVEN( "player is a small size" ) {
-        g->u.empty_traits();
+        g->u.clear_mutations();
         g->u.toggle_trait( trait_id( "SMALL_OK" ) );
 
         WHEN( "the item is a normal size" ) {

tests/new_character_test.cpp

@@ -51,7 +51,7 @@ static std::vector<trait_id> next_subset( const std::vector<trait_id> &set )
 
 static bool try_set_traits( const std::vector<trait_id> &traits )
 {
-    g->u.empty_traits();
+    g->u.clear_mutations();
     g->u.add_traits(); // mandatory prof/scen traits
     for( const trait_id &tr : traits ) {
         if( g->u.has_conflicting_trait( tr ) || !g->scen->traitquery( tr ) ) {

tests/player_helpers.cpp

@@ -55,7 +55,7 @@ void clear_character( player &dummy, bool debug_storage )
     while( dummy.takeoff( dummy.i_at( -2 ), &temp ) );
     dummy.inv.clear();
     dummy.remove_weapon();
-    dummy.empty_traits();
+    dummy.clear_mutations();
 
     // Prevent spilling, but don't cause encumbrance
     if( debug_storage && !dummy.has_trait( trait_id( "DEBUG_STORAGE" ) ) ) {