inherit more exceptions from std::exception

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/ast/datatype_decl_plugin.cpp

@@ -277,7 +277,7 @@ namespace datatype {
         }
 
 
-        struct invalid_datatype {};
+        struct invalid_datatype : public std::exception {};
 
         sort * plugin::mk_sort(decl_kind k, unsigned num_parameters, parameter const * parameters) {
             try {

src/ast/substitution/demodulator_rewriter.cpp

@@ -828,7 +828,7 @@ bool demodulator_match_subst::can_rewrite(expr* n, expr* lhs) {
 */
 struct match_args_aux_proc {
     substitution &                               m_subst;
-    struct no_match {};
+    struct no_match : public std::exception {};
 
     match_args_aux_proc(substitution & s):m_subst(s) {}
 

src/parsers/util/simple_parser.h

@@ -29,7 +29,7 @@ class scanner;
 */
 class simple_parser {
 protected:
-    struct parser_error {};
+    struct parser_error : public std::exception {};
     struct builtin_op {
         family_id m_family_id;
         decl_kind m_kind;

src/qe/qe.cpp

@@ -2456,7 +2456,7 @@ namespace qe {
     }
 
     bool has_quantified_uninterpreted(ast_manager& m, expr* fml) {
-        struct found {};
+        struct found : public std::exception {};
         struct proc {
             ast_manager& m;
             proc(ast_manager& m):m(m) {}

src/sat/dimacs.h

@@ -26,7 +26,7 @@ Revision History:
 bool parse_dimacs(std::istream & s, std::ostream& err, sat::solver & solver);
 
 namespace dimacs {
-    struct lex_error {};
+    struct lex_error : public std::exception {};
 
     class stream_buffer {
         std::istream & m_stream;

src/sat/sat_solver.h

@@ -90,7 +90,7 @@ namespace sat {
     
     class solver : public solver_core {
     public:
-        struct abort_solver {};
+        struct abort_solver : public std::exception {};
     protected:
         enum search_state { s_sat, s_unsat };
 

src/smt/smt_model_finder.cpp

@@ -147,7 +147,7 @@ namespace smt {
                 return m_inv;
             }
 
-            struct is_model_value {};
+            struct is_model_value : public std::exception {};
             void operator()(expr* n) {
                 if (m.is_model_value(n)) {
                     throw is_model_value();
@@ -540,7 +540,7 @@ namespace smt {
                 return !contains_array(e);
             }
 
-            struct found_array {};
+            struct found_array : public std::exception {};
             expr_mark m_visited;
             void operator()(expr* n) {
                 if (m_array.is_array(n))

src/solver/check_logic.cpp

@@ -215,7 +215,7 @@ struct check_logic::imp {
         m_logic = logic;
     }
 
-    struct failed {};
+    struct failed : public std::exception {};
     std::string m_last_error;
 
     void fail(std::string &&msg) {

src/tactic/arith/fix_dl_var_tactic.cpp

@@ -32,7 +32,7 @@ Revision History:
 class fix_dl_var_tactic : public tactic {
 
     struct is_target {
-        struct failed {};
+        struct failed : public std::exception {};
         ast_manager &          m;
         arith_util &           m_util;
         expr_fast_mark1 *      m_visited = nullptr;

src/tactic/arith/lia2pb_tactic.cpp

@@ -86,7 +86,7 @@ class lia2pb_tactic : public tactic {
             return is_target_core(n, u) && u > rational(1);
         }
         
-        struct failed {};
+        struct failed : public std::exception {};
 
         struct visitor {
             imp & m_owner;

src/tactic/bv/bv1_blaster_tactic.cpp

@@ -338,7 +338,7 @@ class bv1_blaster_tactic : public tactic {
             m_rw(m, p) {
         }
 
-        struct not_target {};
+        struct not_target : public std::exception {};
         
         struct visitor {
             family_id m_bv_fid;