#223 add missing return (detected by gcc 11)

src/object.hpp

@@ -44,11 +44,11 @@ struct floating_t {
         mpfr_custom_move(mpfr, significand);
     }
 
-    floating_t& operator=(const double val) { mpfr_set_d(mpfr, val, s_mpfr_rnd); }
+    floating_t& operator=(const double val) { mpfr_set_d(mpfr, val, s_mpfr_rnd); return *this; }
 
-    floating_t& operator=(const long int val) { mpfr_set_si(mpfr, val, s_mpfr_rnd); }
+    floating_t& operator=(const long int val) { mpfr_set_si(mpfr, val, s_mpfr_rnd); return *this; }
 
-    floating_t& operator=(const unsigned long val) { mpfr_set_ui(mpfr, val, s_mpfr_rnd); }
+    floating_t& operator=(const unsigned long val) { mpfr_set_ui(mpfr, val, s_mpfr_rnd); return *this; }
 
     operator double() { return mpfr_get_d(mpfr, s_mpfr_rnd); }
 

src/program.cpp

@@ -1,4 +1,4 @@
-#include "program.hpp"
+ #include "program.hpp"
 
 //< return type strings
 const char* program::s_ret_value_string[ret_max] = RET_VALUE_STRINGS;

src/stack.hpp

@@ -306,6 +306,8 @@ class heap : public stack {
                 ret = true;
             }
         }
+
+        return ret;
     }
 
     /// @brief whether a variable exists in heap or not