Fix Default for floating types and floating to boolean casts (#505)

Author: lucic71

cpp2rust/converter/converter.cpp

@@ -2604,7 +2604,7 @@ void Converter::ConvertIntegralToBooleanCast(clang::ImplicitCastExpr *expr) {
   PushParen paren(*this);
   Convert(sub_expr);
   StrCat(token::kDiff);
-  StrCat(token::kZero);
+  StrCat(sub_expr->getType()->isFloatingType() ? "0.0" : "0");
   computed_expr_type_ = ComputedExprType::FreshValue;
 }
 
@@ -2710,6 +2710,7 @@ bool Converter::VisitImplicitCastExpr(clang::ImplicitCastExpr *expr) {
     Convert(sub_expr);
     break;
   case clang::CastKind::CK_IntegralToBoolean:
+  case clang::CastKind::CK_FloatingToBoolean:
     ConvertIntegralToBooleanCast(expr);
     break;
   case clang::CastKind::CK_PointerToBoolean:

cpp2rust/converter/converter_lib.cpp

@@ -2131,6 +2131,8 @@ clang::Expr *NormalizeToBool(clang::Expr *expr, clang::ASTContext &ctx) {
   clang::CastKind cast_kind;
   if (expr->getType()->isPointerType()) {
     cast_kind = clang::CK_PointerToBoolean;
+  } else if (expr->getType()->isFloatingType()) {
+    cast_kind = clang::CK_FloatingToBoolean;
   } else /* expr->getType()->isIntegerType() */ {
     cast_kind = clang::CK_IntegralToBoolean;
   }

tests/unit/expr_as_bool_cpp.cpp

@@ -55,5 +55,25 @@ int main() {
   assert(both_null(nullptr, nullptr) == 1);
   assert(both_null(p1, nullptr) == 0);
 
+  double d = 0.5;
+  int taken = 0;
+  if (d) {
+    taken = 1;
+  }
+  assert(taken == 1);
+  while (d) {
+    d = 0.0;
+  }
+  assert(d == 0.0);
+
+  float f = 2.0f;
+  bool fb = f;
+  bool nf = !f;
+  assert(fb);
+  assert(!nf);
+  assert(!0.0);
+  int fi = (bool)f;
+  assert(fi == 1);
+
   return 0;
 }

tests/unit/out/refcount/expr_as_bool_cpp.rs

@@ -74,6 +74,24 @@ fn main_0() -> i32 {
     assert!((({ cmp_or_ptr_1(Ptr::<i8>::null(), Ptr::<i8>::null(),) }) == 0));
     assert!((({ both_null_2(Ptr::<i8>::null(), Ptr::<i8>::null(),) }) == 1));
     assert!((({ both_null_2((p1).clone(), Ptr::<i8>::null(),) }) == 0));
+    let mut d: f64 = 0.5_f64;
+    let mut taken: i32 = 0;
+    if (d != 0.0) {
+        taken = 1;
+    }
+    assert!((taken == 1));
+    'loop_: while (d != 0.0) {
+        d = 0_f64;
+    }
+    assert!((d == 0_f64));
+    let mut f: f32 = 2_f32;
+    let mut fb: bool = (f != 0.0);
+    let mut nf: bool = !(f != 0.0);
+    assert!(fb);
+    assert!(!(nf));
+    assert!(!(0_f64 != 0.0));
+    let mut fi: i32 = ((f != 0.0) as i32);
+    assert!((fi == 1));
     return 0;
 }
 pub fn __cpp2rust_init_globals() {}

tests/unit/out/unsafe/expr_as_bool_cpp.rs

@@ -76,6 +76,24 @@ unsafe fn main_0() -> i32 {
     assert!(((unsafe { cmp_or_ptr_1(std::ptr::null(), std::ptr::null(),) }) == (0)));
     assert!(((unsafe { both_null_2(std::ptr::null(), std::ptr::null(),) }) == (1)));
     assert!(((unsafe { both_null_2(p1, std::ptr::null(),) }) == (0)));
+    let mut d: f64 = 0.5_f64;
+    let mut taken: i32 = 0;
+    if (d != 0.0) {
+        taken = 1;
+    }
+    assert!(((taken) == (1)));
+    'loop_: while (d != 0.0) {
+        d = 0_f64;
+    }
+    assert!(((d) == (0_f64)));
+    let mut f: f32 = 2_f32;
+    let mut fb: bool = (f != 0.0);
+    let mut nf: bool = !(f != 0.0);
+    assert!(fb);
+    assert!(!(nf));
+    assert!(!(0_f64 != 0.0));
+    let mut fi: i32 = ((f != 0.0) as i32);
+    assert!(((fi) == (1)));
     return 0;
 }
 pub unsafe fn __cpp2rust_init_globals() {}