Fix small contract implementation bugs and a signedness test error

Author: hsutter

include/cpp2util.h

@@ -401,7 +401,7 @@ class contract_group {
     constexpr auto has_handler() const -> bool    { return reporter != handler{}; }
 
     constexpr auto enforce(bool b, CPP2_MESSAGE_PARAM msg = "" CPP2_SOURCE_LOCATION_PARAM_WITH_DEFAULT)
-                                          -> void { if (!b) reporter(msg CPP2_SOURCE_LOCATION_ARG); }
+                                          -> void { if (!b) report_violation(msg CPP2_SOURCE_LOCATION_ARG); }
     constexpr auto report_violation(CPP2_MESSAGE_PARAM msg = "" CPP2_SOURCE_LOCATION_PARAM_WITH_DEFAULT)
                                           -> void { if (reporter) reporter(msg CPP2_SOURCE_LOCATION_ARG); }
 private:
@@ -515,7 +515,7 @@ auto assert_in_bounds_impl(auto&&, auto&& CPP2_SOURCE_LOCATION_PARAM_WITH_DEFAUL
     if (msg) {
         err += " and the message \"" + msg + "\"";
     }
-    Type.report_violation( msg );
+    Type.report_violation( err );
     std::terminate();
 #else
     throw CPP2_FORWARD(x);

regression-tests/pure2-print.cpp2

@@ -92,7 +92,7 @@ outer: @print type = {
         tup: std::tuple<Ts...> = ();
     }
 
-    print: <Args...: type> (inout out: std::ostream, args...: Args) requires sizeof...(Args) >= 0 = {
+    print: <Args...: type> (inout out: std::ostream, args...: Args) requires sizeof...(Args) >= 0u = {
         (out << ... << args);
     }
 

regression-tests/test-results/gcc-10/pure2-print.cpp.output

@@ -12,6 +12,6 @@ pure2-print.cpp2:9:48: error: template definition of non-template ‘constexpr c
 pure2-print.cpp2:67:14: error: no declaration matches ‘void outer::mytype::variadic(const auto:91& ...) requires (is_convertible_v<typename std::remove_cv<typename std::remove_reference<decltype(outer::mytype::variadic::x)>::type>::type, int> && ...)’
 pure2-print.cpp2:67:29: note: candidate is: ‘template<class ... auto:90> static void outer::mytype::variadic(const auto:90& ...)’
 pure2-print.cpp2:10:19: note: ‘class outer::mytype’ defined here
-pure2-print.cpp2:95:37: error: no declaration matches ‘void outer::print(std::ostream&, const Args& ...) requires  cpp2::cmp_greater_eq(sizeof (Args)..., 0)’
-pure2-print.cpp2:95:37: note: no functions named ‘void outer::print(std::ostream&, const Args& ...) requires  cpp2::cmp_greater_eq(sizeof (Args)..., 0)’
+pure2-print.cpp2:95:37: error: no declaration matches ‘void outer::print(std::ostream&, const Args& ...) requires  cpp2::cmp_greater_eq(sizeof ... (Args ...), 0)’
+pure2-print.cpp2:95:37: note: no functions named ‘void outer::print(std::ostream&, const Args& ...) requires  cpp2::cmp_greater_eq(sizeof ... (Args ...), 0)’
 pure2-print.cpp2:6:7: note: ‘class outer’ defined here

regression-tests/test-results/pure2-print.cpp

@@ -66,7 +66,7 @@ CPP2_REQUIRES_ ((std::is_convertible_v<CPP2_TYPEOF(x), int> && ...)) ;
     };
 
     public: template<typename ...Args> static auto print(std::ostream& out, Args const& ...args) -> void
-CPP2_REQUIRES_ (cpp2::cmp_greater_eq(sizeof...(Args),0)) ;
+CPP2_REQUIRES_ (cpp2::cmp_greater_eq(sizeof...(Args),0u)) ;
 
 #line 99 "pure2-print.cpp2"
     public: template<typename ...Args> [[nodiscard]] static auto all(Args const& ...args) -> bool;
@@ -182,7 +182,7 @@ requires ((std::is_convertible_v<CPP2_TYPEOF(x), int> && ...)) {(std::cout << ..
 
 #line 95 "pure2-print.cpp2"
     template<typename ...Args> auto outer::print(std::ostream& out, Args const& ...args) -> void
-requires (cpp2::cmp_greater_eq(sizeof...(Args),0)) {
+requires (cpp2::cmp_greater_eq(sizeof...(Args),0u)) {
 #line 96 "pure2-print.cpp2"
         (out << ... << args);
     }

regression-tests/test-results/pure2-print.cpp2.output

@@ -139,7 +139,7 @@ outer: type =
     print: <Args...: type>(
         inout out: std::ostream, 
         in args...: Args
-    ) requires (sizeof...(Args) >= 0) = 
+    ) requires (sizeof...(Args) >= 0u) = 
     {
         (out << ... << args);
     }