1 files changed, 23 insertions, 3 deletions

diff --git a/src/keeper.cpp b/src/keeper.cpp
index 7619eb4..2e13de3 100644
--- a/src/keeper.cpp
+++ b/src/keeper.cpp
@@ -104,6 +104,7 @@ class KeyUD final
 
 // #################################################################################################
 
+[[nodiscard]]
 bool KeyUD::changeLimit(LindaLimit const limit_)
 {
     bool const _newSlackAvailable{
@@ -127,6 +128,7 @@ LindaRestrict KeyUD::changeRestrict(LindaRestrict const restrict_)
 
 // in: nothing
 // out: { first = 1, count = 0, limit = -1}
+[[nodiscard]]
 KeyUD* KeyUD::Create(KeeperState const K_)
 {
     STACK_GROW(K_, 2);
@@ -141,6 +143,7 @@ KeyUD* KeyUD::Create(KeeperState const K_)
 
 // #################################################################################################
 
+[[nodiscard]]
 KeyUD* KeyUD::GetPtr(KeeperState const K_, StackIndex const idx_)
 {
     return luaG_tofulluserdata<KeyUD>(K_, idx_);
@@ -181,6 +184,7 @@ void KeyUD::peek(KeeperState const K_, int const count_) const
 
 // in: fifo
 // out: remove the fifo table from the stack, push as many items as required on the stack (function assumes they exist in sufficient number)
+[[nodiscard]]
 int KeyUD::pop(KeeperState const K_, int const minCount_, int const maxCount_)
 {
     if (count < minCount_) {
@@ -243,6 +247,7 @@ void KeyUD::prepareAccess(KeeperState const K_, StackIndex const idx_) const
 
 // in: expect this val... on top of the stack
 // out: nothing, removes all pushed values from the stack
+[[nodiscard]]
 bool KeyUD::push(KeeperState const K_, int const count_, bool const enforceLimit_)
 {
     StackIndex const _fifoIdx{ luaG_absindex(K_, StackIndex{ -1 - count_ }) };
@@ -272,7 +277,7 @@ void KeyUD::pushFillStatus(KeeperState const K_) const
         luaG_pushstring(K_, kUnder);
         return;
     }
-    int const _delta{limit - count};
+    int const _delta{ limit - count };
     if (_delta < 0) {
         luaG_pushstring(K_, kOver);
     } else if (_delta > 0) {
@@ -295,7 +300,10 @@ void KeyUD::PushFillStatus(KeeperState const K_, KeyUD const* const key_)
 
 // #################################################################################################
 
-// expects 'this' on top of the stack
+// in: expects 'this' on top of the stack
+// out: nothing
+// returns true if the channel was full
+[[nodiscard]]
 bool KeyUD::reset(KeeperState const K_)
 {
     LUA_ASSERT(K_, KeyUD::GetPtr(K_, kIdxTop) == this);
@@ -347,6 +355,7 @@ static void PushKeysDB(KeeperState const K_, StackIndex const idx_)
 
 // in: linda
 // out: nothing
+[[nodiscard]]
 int keepercall_collectgarbage(lua_State* const L_)
 {
     lua_gc(L_, LUA_GCCOLLECT, 0);
@@ -356,6 +365,7 @@ int keepercall_collectgarbage(lua_State* const L_)
 // #################################################################################################
 
 // in: linda [, key [, ...]]
+[[nodiscard]]
 int keepercall_count(lua_State* const L_)
 {
     KeeperState const _K{ L_ };
@@ -419,6 +429,7 @@ int keepercall_count(lua_State* const L_)
 
 // in: linda
 // not part of the linda public API, only used for cleanup at linda GC
+[[nodiscard]]
 int keepercall_destruct(lua_State* const L_)
 {
     STACK_GROW(L_, 3);
@@ -437,6 +448,7 @@ int keepercall_destruct(lua_State* const L_)
 
 // in: linda_ud key [count]
 // out: N <N values>|kRestrictedChannel
+[[nodiscard]]
 int keepercall_get(lua_State* const L_)
 {
     KeeperState const _K{ L_ };
@@ -471,6 +483,7 @@ int keepercall_get(lua_State* const L_)
 
 // in: linda key [n|nil]
 // out: boolean, <fill status: string>
+[[nodiscard]]
 int keepercall_limit(lua_State* const L_)
 {
     KeeperState const _K{ L_ };
@@ -514,6 +527,7 @@ int keepercall_limit(lua_State* const L_)
 
 // in: linda, key [, key]?
 // out: (key, val) or nothing
+[[nodiscard]]
 int keepercall_receive(lua_State* const L_)
 {
     KeeperState const _K{ L_ };
@@ -558,6 +572,7 @@ int keepercall_receive(lua_State* const L_)
 // #################################################################################################
 
 // in: linda key mincount [maxcount]
+[[nodiscard]]
 int keepercall_receive_batched(lua_State* const L_)
 {
     KeeperState const _K{ L_ };
@@ -591,6 +606,7 @@ int keepercall_receive_batched(lua_State* const L_)
 
 // in: linda key [mode]
 // out: mode
+[[nodiscard]]
 int keepercall_restrict(lua_State* const L_)
 {
     KeeperState const _K{ L_ };
@@ -655,6 +671,7 @@ int keepercall_restrict(lua_State* const L_)
 
 // in: linda, key, ...
 // out: true|false|kRestrictedChannel
+[[nodiscard]]
 int keepercall_send(lua_State* const L_)
 {
     KeeperState const _K{ L_ };
@@ -694,6 +711,7 @@ int keepercall_send(lua_State* const L_)
 
 // in: linda key [val...]
 // out: true if the linda was full but it's no longer the case, else false, or kRestrictedChannel if the key is restricted
+[[nodiscard]]
 int keepercall_set(lua_State* const L_)
 {
     KeeperState const _K{ L_ };
@@ -763,6 +781,7 @@ int keepercall_set(lua_State* const L_)
  *
  * Returns: number of return values (pushed to 'L'), unset in case of error
  */
+[[nodiscard]]
 KeeperCallResult keeper_call(KeeperState const K_, keeper_api_t const func_, lua_State* const L_, Linda* const linda_, StackIndex const starting_index_)
 {
     KeeperCallResult _result;
@@ -832,6 +851,7 @@ KeeperCallResult keeper_call(KeeperState const K_, keeper_api_t const func_, lua
 //     }
 //     ...
 // }
+[[nodiscard]]
 int Keeper::PushLindaStorage(Linda& linda_, DestState const L_)
 {
     Keeper* const _keeper{ linda_.whichKeeper() };
@@ -961,7 +981,7 @@ void Keepers::collectGarbage()
 
 // #################################################################################################
 
-
+[[nodiscard]]
 bool Keepers::close()
 {
     if (isClosing.test_and_set(std::memory_order_release)) {