diff --git a/.github/workflows/format.yml b/.github/workflows/format.yml
index 8d020676..9591ca4d 100644
--- a/.github/workflows/format.yml
+++ b/.github/workflows/format.yml
@@ -23,7 +23,7 @@ jobs:
           echo "$HOME/.cargo/bin" >> $GITHUB_PATH
 
       - name: Check C++ formatting
-        run: find cpp2rust tests -name '*.cpp' -o -name '*.h' | xargs clang-format --dry-run --Werror
+        run: find cpp2rust tests -name '*.cpp' -o -name '*.h' -o -name '*.c' | xargs clang-format --dry-run --Werror
 
       - name: Check Rust formatting
         run: |
diff --git a/CMakeLists.txt b/CMakeLists.txt
index b880ff79..05b17078 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -93,7 +93,7 @@ add_subdirectory(tests)
 find_program(CLANG_FORMAT NAMES clang-format-22 clang-format)
 
 file(GLOB_RECURSE ALL_CXX_SOURCES
-     cpp2rust/*.cpp cpp2rust/*.h tests/*.cpp)
+     cpp2rust/*.cpp cpp2rust/*.h tests/*.cpp tests/*.c)
 
 add_custom_target("format"
                   COMMAND ${CLANG_FORMAT} -i ${ALL_CXX_SOURCES}
diff --git a/cpp2rust/CMakeLists.txt b/cpp2rust/CMakeLists.txt
index 4719cd4b..ce30f0a9 100644
--- a/cpp2rust/CMakeLists.txt
+++ b/cpp2rust/CMakeLists.txt
@@ -13,7 +13,8 @@ target_link_libraries(cpp2rust PRIVATE
 target_include_directories(cpp2rust PUBLIC ${CMAKE_CURRENT_SOURCE_DIR})
 target_include_directories(cpp2rust PUBLIC SYSTEM ${CLANG_INCLUDE_DIRS} ${LLVM_INCLUDE_DIRS})
 target_compile_definitions(cpp2rust PUBLIC ${LLVM_DEFINITIONS})
-target_compile_definitions(cpp2rust PUBLIC "-DCLANG_EXECUTABLE=\"${CMAKE_CXX_COMPILER}\"")
+target_compile_definitions(cpp2rust PUBLIC "-DCLANG_C_COMPILER=\"${CMAKE_C_COMPILER}\"")
+target_compile_definitions(cpp2rust PUBLIC "-DCLANG_CXX_COMPILER=\"${CMAKE_CXX_COMPILER}\"")
 target_compile_definitions(cpp2rust PUBLIC "-DCLANG_RESOURCE_DIR=\"${LLVM_LIBRARY_DIR}/clang/${LLVM_VERSION_MAJOR}\"")
 target_compile_definitions(cpp2rust PUBLIC "-DCOMPAT_INCLUDE_DIR=\"${CMAKE_CURRENT_SOURCE_DIR}/compat\"")
 
diff --git a/cpp2rust/converter/converter.cpp b/cpp2rust/converter/converter.cpp
index 67afae39..b358f553 100644
--- a/cpp2rust/converter/converter.cpp
+++ b/cpp2rust/converter/converter.cpp
@@ -916,9 +916,18 @@ bool Converter::VisitReturnStmt(clang::ReturnStmt *stmt) {
   return false;
 }
 
+void Converter::ConvertCondition(clang::Expr *cond) {
+  if (!cond->getType()->isBooleanType()) {
+    PushExprKind push(*this, ExprKind::RValue);
+    Convert(CreateConversionToBool(cond, ctx_));
+    return;
+  }
+  Convert(cond);
+}
+
 bool Converter::VisitIfStmt(clang::IfStmt *stmt) {
   StrCat(keyword::kIf);
-  Convert(stmt->getCond());
+  ConvertCondition(stmt->getCond());
   StrCat(token::kOpenCurlyBracket);
   Convert(stmt->getThen());
   StrCat(token::kCloseCurlyBracket);
@@ -938,7 +947,7 @@ bool Converter::VisitIfStmt(clang::IfStmt *stmt) {
 bool Converter::VisitWhileStmt(clang::WhileStmt *stmt) {
   StrCat("'loop_:");
   StrCat(keyword::kWhile);
-  Convert(stmt->getCond());
+  ConvertCondition(stmt->getCond());
   StrCat(token::kOpenCurlyBracket);
   curr_for_inc_.emplace(nullptr);
   Convert(stmt->getBody());
@@ -954,7 +963,7 @@ bool Converter::VisitDoStmt(clang::DoStmt *stmt) {
   Convert(stmt->getBody());
   curr_for_inc_.pop();
   StrCat(keyword::kIf, token::kNot, token::kOpenParen);
-  Convert(stmt->getCond());
+  ConvertCondition(stmt->getCond());
   StrCat(token::kCloseParen, token::kOpenCurlyBracket, keyword::kBreak,
          token::kSemiColon, token::kCloseCurlyBracket,
          token::kCloseCurlyBracket);
@@ -968,7 +977,7 @@ bool Converter::VisitForStmt(clang::ForStmt *stmt) {
   if (stmt->getCond() == nullptr) {
     StrCat("true");
   } else {
-    Convert(stmt->getCond());
+    ConvertCondition(stmt->getCond());
   }
   StrCat(token::kOpenCurlyBracket);
   curr_for_inc_.emplace(stmt->getInc());
@@ -1546,7 +1555,8 @@ bool Converter::VisitFloatingLiteral(clang::FloatingLiteral *expr) {
 bool Converter::VisitCharacterLiteral(clang::CharacterLiteral *expr) {
   std::string ch = GetEscapedCharLiteral(expr->getValue());
   ch = "'" + std::move(ch) + "'";
-  StrCat(token::kOpenParen, ch, keyword::kAs, "u8", token::kCloseParen);
+  StrCat(token::kOpenParen, ch, keyword::kAs, ToStringBase(expr->getType()),
+         token::kCloseParen);
   computed_expr_type_ = ComputedExprType::FreshValue;
   return false;
 }
@@ -1664,6 +1674,15 @@ bool Converter::VisitImplicitCastExpr(clang::ImplicitCastExpr *expr) {
     Convert(sub_expr);
     break;
   case clang::CastKind::CK_IntegralToBoolean:
+    if (auto binop = clang::dyn_cast<clang::BinaryOperator>(
+            sub_expr->IgnoreParenImpCasts())) {
+      // This already produces bool, no need for != 0
+      if (binop->isComparisonOp()) {
+        Convert(sub_expr);
+        break;
+      }
+    }
+
     StrCat(token::kOpenParen);
     Convert(sub_expr);
     StrCat(token::kDiff, token::kZero, token::kCloseParen);
@@ -2875,12 +2894,12 @@ void Converter::ConvertAssignment(clang::Expr *lhs, clang::Expr *rhs,
   curr_init_type_.pop();
   auto rhs_as_string = ConvertFreshRValue(rhs);
 
-  if (isRValue()) {
+  if (!isVoid()) {
     StrCat(token::kOpenCurlyBracket);
   }
 
   StrCat(lhs_as_string, assign_operator, rhs_as_string);
-  if (isRValue()) {
+  if (!isVoid()) {
     StrCat(token::kSemiColon, ConvertRValue(lhs), token::kCloseCurlyBracket);
   }
 }
diff --git a/cpp2rust/converter/converter.h b/cpp2rust/converter/converter.h
index 899cc965..bcc0d538 100644
--- a/cpp2rust/converter/converter.h
+++ b/cpp2rust/converter/converter.h
@@ -112,6 +112,8 @@ class Converter : public clang::RecursiveASTVisitor<Converter> {
 
   virtual bool VisitReturnStmt(clang::ReturnStmt *stmt);
 
+  void ConvertCondition(clang::Expr *cond);
+
   virtual bool VisitIfStmt(clang::IfStmt *stmt);
 
   virtual bool VisitWhileStmt(clang::WhileStmt *stmt);
diff --git a/cpp2rust/converter/converter_lib.cpp b/cpp2rust/converter/converter_lib.cpp
index c70ed407..3f515788 100644
--- a/cpp2rust/converter/converter_lib.cpp
+++ b/cpp2rust/converter/converter_lib.cpp
@@ -654,4 +654,10 @@ bool ContainsVAArgExpr(const clang::Stmt *stmt) {
   return false;
 }
 
+clang::Expr *CreateConversionToBool(clang::Expr *expr, clang::ASTContext &ctx) {
+  return clang::ImplicitCastExpr::Create(
+      ctx, ctx.BoolTy, clang::CK_IntegralToBoolean, expr,
+      /*BasePath=*/nullptr, clang::VK_PRValue, clang::FPOptionsOverride());
+}
+
 } // namespace cpp2rust
diff --git a/cpp2rust/converter/converter_lib.h b/cpp2rust/converter/converter_lib.h
index c0d2a65d..3696d680 100644
--- a/cpp2rust/converter/converter_lib.h
+++ b/cpp2rust/converter/converter_lib.h
@@ -152,4 +152,6 @@ bool IsBuiltinVaCopy(const clang::CallExpr *expr);
 
 bool ContainsVAArgExpr(const clang::Stmt *stmt);
 
+clang::Expr *CreateConversionToBool(clang::Expr *expr, clang::ASTContext &ctx);
+
 } // namespace cpp2rust
diff --git a/cpp2rust/converter/models/converter_refcount.cpp b/cpp2rust/converter/models/converter_refcount.cpp
index 7d98708f..714c2ffd 100644
--- a/cpp2rust/converter/models/converter_refcount.cpp
+++ b/cpp2rust/converter/models/converter_refcount.cpp
@@ -188,7 +188,7 @@ bool ConverterRefCount::VisitPointerType(clang::PointerType *type) {
   PushConversionKind push2(*this, ConversionKind::FullRefCount,
                            pointee_type->isArrayType());
   if (pointee_type->isRecordType() &&
-      abstract_structs_.contains(GetID(pointee_type->getAsCXXRecordDecl()))) {
+      abstract_structs_.contains(GetID(pointee_type->getAsRecordDecl()))) {
     StrCat("PtrDyn<dyn");
   } else {
     StrCat("Ptr<");
diff --git a/cpp2rust/cpp2rust.cpp b/cpp2rust/cpp2rust.cpp
index f7943b6f..1b929d5d 100644
--- a/cpp2rust/cpp2rust.cpp
+++ b/cpp2rust/cpp2rust.cpp
@@ -150,7 +150,7 @@ int main(int argc, char *argv[]) {
 
   auto rs_code =
       BuildDir.empty()
-          ? cpp2rust::TranspileSrc(cc_code, model, cxx_flags, RulesDir)
+          ? cpp2rust::TranspileSrc(cc_code, model, cxx_flags, RulesDir, CcFile)
           : cpp2rust::TranspileDir(BuildDir, model, RulesDir);
 
   if (rs_code.empty()) {
diff --git a/cpp2rust/cpp2rust_lib.cpp b/cpp2rust/cpp2rust_lib.cpp
index 7c2654ea..549e1619 100644
--- a/cpp2rust/cpp2rust_lib.cpp
+++ b/cpp2rust/cpp2rust_lib.cpp
@@ -13,7 +13,8 @@
 namespace cpp2rust {
 std::string TranspileSrc(std::string_view cc_code, Model model,
                          const std::vector<std::string_view> &cxx_flags,
-                         const std::string &rules_dir) {
+                         const std::string &rules_dir,
+                         std::string_view filename) {
   auto tool_args = getPlatformClangFlags();
   tool_args.push_back("-fparse-all-comments");
   tool_args.insert(tool_args.end(), cxx_flags.begin(), cxx_flags.end());
@@ -21,7 +22,8 @@ std::string TranspileSrc(std::string_view cc_code, Model model,
   std::string rs_code;
   clang::tooling::runToolOnCodeWithArgs(
       std::make_unique<FrontendAction>(rs_code, model, true, rules_dir),
-      cc_code, tool_args, "input.cpp", CLANG_EXECUTABLE);
+      cc_code, tool_args, filename.ends_with(".c") ? "input.c" : "input.cpp",
+      filename.ends_with(".c") ? CLANG_C_COMPILER : CLANG_CXX_COMPILER);
   return rs_code;
 }
 
diff --git a/cpp2rust/cpp2rust_lib.h b/cpp2rust/cpp2rust_lib.h
index 544d72a7..9c87db2e 100644
--- a/cpp2rust/cpp2rust_lib.h
+++ b/cpp2rust/cpp2rust_lib.h
@@ -12,7 +12,8 @@ namespace cpp2rust {
 
 std::string TranspileSrc(std::string_view cc_code, Model model,
                          const std::vector<std::string_view> &cxx_flags,
-                         const std::string &rules_dir);
+                         const std::string &rules_dir,
+                         std::string_view filename);
 std::string TranspileDir(std::string_view build_dir, Model model,
                          const std::string &rules_dir);
 
diff --git a/tests/lit/lit/formats/Cpp2RustTest.py b/tests/lit/lit/formats/Cpp2RustTest.py
index 1f0d54da..a9b87106 100644
--- a/tests/lit/lit/formats/Cpp2RustTest.py
+++ b/tests/lit/lit/formats/Cpp2RustTest.py
@@ -48,7 +48,7 @@ def getTestsInDirectory(self, testSuite, path_in_suite,
                           litConfig, localConfig):
     source_path = testSuite.getSourcePath(path_in_suite)
     for filename in os.listdir(source_path):
-      if filename.endswith('.cpp'):
+      if filename.endswith('.cpp') or filename.endswith('.c'):
         for t in self.getTestsForPath(testSuite, path_in_suite + (filename,), litConfig, localConfig):
           yield t
 
@@ -172,10 +172,11 @@ def fail(str, code = fail_code):
       elif is_nondet_result:
         lit.util.executeCommand(rust_bin)
       else:
-        cmd = ['clang++', '-O3', '-o', tmp_dir + '/cpp', cc_input]
+        cc = 'clang' if cc_input.endswith('.c') else 'clang++'
+        cmd = [cc, '-O3', '-o', tmp_dir + '/cpp', cc_input]
         _, _, code = lit.util.executeCommand(cmd)
         if code != 0:
-          return fail('clang++ failed')
+          return fail(cc + ' failed')
 
         out_cpp, err_cpp, code_cpp = lit.util.executeCommand(tmp_dir + '/cpp')
         out_rs, err_rs, code_rs = lit.util.executeCommand(rust_bin)
diff --git a/tests/unit/expr_as_bool_c.c b/tests/unit/expr_as_bool_c.c
new file mode 100644
index 00000000..3a7cc106
--- /dev/null
+++ b/tests/unit/expr_as_bool_c.c
@@ -0,0 +1,29 @@
+#include <assert.h>
+#include <stdbool.h>
+
+int main() {
+  int a = 0;
+  int b;
+
+  if (b = a) {
+  }
+  while ((b = a) != 0) {
+  }
+  if (a) {
+  }
+  if (a == b) {
+  }
+  if (a < b) {
+  }
+
+  assert(a == b);
+  assert(!(a = b));
+
+  bool c;
+  c = a = b;
+  c = (b = a) != 0;
+  c = a;
+  c = a == b;
+  c = a < b;
+  return 0;
+}
diff --git a/tests/unit/expr_as_bool_cpp.cpp b/tests/unit/expr_as_bool_cpp.cpp
new file mode 100644
index 00000000..3a7cc106
--- /dev/null
+++ b/tests/unit/expr_as_bool_cpp.cpp
@@ -0,0 +1,29 @@
+#include <assert.h>
+#include <stdbool.h>
+
+int main() {
+  int a = 0;
+  int b;
+
+  if (b = a) {
+  }
+  while ((b = a) != 0) {
+  }
+  if (a) {
+  }
+  if (a == b) {
+  }
+  if (a < b) {
+  }
+
+  assert(a == b);
+  assert(!(a = b));
+
+  bool c;
+  c = a = b;
+  c = (b = a) != 0;
+  c = a;
+  c = a == b;
+  c = a < b;
+  return 0;
+}
diff --git a/tests/unit/out/refcount/expr_as_bool.rs b/tests/unit/out/refcount/expr_as_bool.rs
new file mode 100644
index 00000000..a257e1b8
--- /dev/null
+++ b/tests/unit/out/refcount/expr_as_bool.rs
@@ -0,0 +1,22 @@
+extern crate libcc2rs;
+use libcc2rs::*;
+use std::cell::RefCell;
+use std::collections::BTreeMap;
+use std::io::prelude::*;
+use std::io::Seek;
+use std::io::{Read, Write};
+use std::os::fd::AsFd;
+use std::rc::{Rc, Weak};
+pub fn main() {
+    std::process::exit(main_0());
+}
+fn main_0() -> i32 {
+    let a: Value<i32> = Rc::new(RefCell::new(0));
+    let b: Value<i32> = <Value<i32>>::default();
+    if ({
+        (*b.borrow_mut()) = (*a.borrow());
+        (*b.borrow())
+    } != 0)
+    {}
+    return 0;
+}
diff --git a/tests/unit/out/refcount/expr_as_bool_c.rs b/tests/unit/out/refcount/expr_as_bool_c.rs
new file mode 100644
index 00000000..c1b22fc5
--- /dev/null
+++ b/tests/unit/out/refcount/expr_as_bool_c.rs
@@ -0,0 +1,52 @@
+extern crate libcc2rs;
+use libcc2rs::*;
+use std::cell::RefCell;
+use std::collections::BTreeMap;
+use std::io::prelude::*;
+use std::io::Seek;
+use std::io::{Read, Write};
+use std::os::fd::AsFd;
+use std::rc::{Rc, Weak};
+pub fn main() {
+    std::process::exit(main_0());
+}
+fn main_0() -> i32 {
+    let a: Value<i32> = Rc::new(RefCell::new(0));
+    let b: Value<i32> = <Value<i32>>::default();
+    if ({
+        (*b.borrow_mut()) = (*a.borrow());
+        (*b.borrow())
+    } != 0)
+    {}
+    'loop_: while ((({
+        (*b.borrow_mut()) = (*a.borrow());
+        (*b.borrow())
+    }) as i32)
+        != 0)
+    {}
+    if ((*a.borrow()) != 0) {}
+    if ((*a.borrow()) == (*b.borrow())) {}
+    if ((*a.borrow()) < (*b.borrow())) {}
+    assert!(((*a.borrow()) == (*b.borrow())));
+    assert!(
+        (!(({
+            (*a.borrow_mut()) = (*b.borrow());
+            (*a.borrow())
+        }) as i32)
+            != 0)
+    );
+    let c: Value<bool> = <Value<bool>>::default();
+    (*c.borrow_mut()) = ({
+        (*a.borrow_mut()) = (*b.borrow());
+        (*a.borrow())
+    } != 0);
+    (*c.borrow_mut()) = ((({
+        (*b.borrow_mut()) = (*a.borrow());
+        (*b.borrow())
+    }) as i32)
+        != 0);
+    (*c.borrow_mut()) = ((*a.borrow()) != 0);
+    (*c.borrow_mut()) = ((*a.borrow()) == (*b.borrow()));
+    (*c.borrow_mut()) = ((*a.borrow()) < (*b.borrow()));
+    return 0;
+}
diff --git a/tests/unit/out/refcount/expr_as_bool_cpp.rs b/tests/unit/out/refcount/expr_as_bool_cpp.rs
new file mode 100644
index 00000000..5cf39984
--- /dev/null
+++ b/tests/unit/out/refcount/expr_as_bool_cpp.rs
@@ -0,0 +1,52 @@
+extern crate libcc2rs;
+use libcc2rs::*;
+use std::cell::RefCell;
+use std::collections::BTreeMap;
+use std::io::prelude::*;
+use std::io::Seek;
+use std::io::{Read, Write};
+use std::os::fd::AsFd;
+use std::rc::{Rc, Weak};
+pub fn main() {
+    std::process::exit(main_0());
+}
+fn main_0() -> i32 {
+    let a: Value<i32> = Rc::new(RefCell::new(0));
+    let b: Value<i32> = <Value<i32>>::default();
+    if ({
+        (*b.borrow_mut()) = (*a.borrow());
+        (*b.borrow())
+    } != 0)
+    {}
+    'loop_: while ((({
+        (*b.borrow_mut()) = (*a.borrow());
+        (*b.borrow())
+    }) as i32)
+        != 0)
+    {}
+    if ((*a.borrow()) != 0) {}
+    if ((*a.borrow()) == (*b.borrow())) {}
+    if ((*a.borrow()) < (*b.borrow())) {}
+    assert!(((*a.borrow()) == (*b.borrow())));
+    assert!(
+        !((({
+            (*a.borrow_mut()) = (*b.borrow());
+            (*a.borrow())
+        }) as i32)
+            != 0)
+    );
+    let c: Value<bool> = <Value<bool>>::default();
+    (*c.borrow_mut()) = ({
+        (*a.borrow_mut()) = (*b.borrow());
+        (*a.borrow())
+    } != 0);
+    (*c.borrow_mut()) = ((({
+        (*b.borrow_mut()) = (*a.borrow());
+        (*b.borrow())
+    }) as i32)
+        != 0);
+    (*c.borrow_mut()) = ((*a.borrow()) != 0);
+    (*c.borrow_mut()) = ((*a.borrow()) == (*b.borrow()));
+    (*c.borrow_mut()) = ((*a.borrow()) < (*b.borrow()));
+    return 0;
+}
diff --git a/tests/unit/out/refcount/va_arg_chain.rs b/tests/unit/out/refcount/va_arg_chain.rs
index 0dbdeef3..a08b1106 100644
--- a/tests/unit/out/refcount/va_arg_chain.rs
+++ b/tests/unit/out/refcount/va_arg_chain.rs
@@ -28,7 +28,7 @@ pub fn middle_layer_1(n: i32, ap: VaList) -> i32 {
 }
 pub fn top_level_2(n: i32, args: &[VaArg]) -> i32 {
     let n: Value<i32> = Rc::new(RefCell::new(n));
-    let ap: Value<VaList> = Rc::new(RefCell::new(<VaList>::default()));
+    let ap: Value<VaList> = <Value<VaList>>::default();
     (*ap.borrow_mut()) = VaList::new(args);
     let result: Value<i32> = Rc::new(RefCell::new(
         ({
diff --git a/tests/unit/out/refcount/va_arg_concat.rs b/tests/unit/out/refcount/va_arg_concat.rs
index c39321b1..e59f12a2 100644
--- a/tests/unit/out/refcount/va_arg_concat.rs
+++ b/tests/unit/out/refcount/va_arg_concat.rs
@@ -9,7 +9,7 @@ use std::os::fd::AsFd;
 use std::rc::{Rc, Weak};
 pub fn sum_ints_0(first: i32, args: &[VaArg]) -> i32 {
     let first: Value<i32> = Rc::new(RefCell::new(first));
-    let ap: Value<VaList> = Rc::new(RefCell::new(<VaList>::default()));
+    let ap: Value<VaList> = <Value<VaList>>::default();
     let total: Value<i32> = Rc::new(RefCell::new((*first.borrow())));
     (*ap.borrow_mut()) = VaList::new(args);
     let val: Value<i32> = <Value<i32>>::default();
diff --git a/tests/unit/out/refcount/va_arg_conditional.rs b/tests/unit/out/refcount/va_arg_conditional.rs
index 5717a301..f2bdf8ab 100644
--- a/tests/unit/out/refcount/va_arg_conditional.rs
+++ b/tests/unit/out/refcount/va_arg_conditional.rs
@@ -11,7 +11,7 @@ pub fn conditional_log_0(verbose: i32, fmt: Ptr<u8>, args: &[VaArg]) -> i32 {
     let verbose: Value<i32> = Rc::new(RefCell::new(verbose));
     let fmt: Value<Ptr<u8>> = Rc::new(RefCell::new(fmt));
     if ((*verbose.borrow()) != 0) {
-        let ap: Value<VaList> = Rc::new(RefCell::new(<VaList>::default()));
+        let ap: Value<VaList> = <Value<VaList>>::default();
         (*ap.borrow_mut()) = VaList::new(args);
         let result: Value<i32> = Rc::new(RefCell::new(((*ap.borrow_mut()).arg::<i32>()).clone()));
         return (*result.borrow());
diff --git a/tests/unit/out/refcount/va_arg_copy.rs b/tests/unit/out/refcount/va_arg_copy.rs
index f5cabeb4..3cc524fe 100644
--- a/tests/unit/out/refcount/va_arg_copy.rs
+++ b/tests/unit/out/refcount/va_arg_copy.rs
@@ -9,8 +9,8 @@ use std::os::fd::AsFd;
 use std::rc::{Rc, Weak};
 pub fn sum_with_copy_0(count: i32, args: &[VaArg]) -> i32 {
     let count: Value<i32> = Rc::new(RefCell::new(count));
-    let ap: Value<VaList> = Rc::new(RefCell::new(<VaList>::default()));
-    let aq: Value<VaList> = Rc::new(RefCell::new(<VaList>::default()));
+    let ap: Value<VaList> = <Value<VaList>>::default();
+    let aq: Value<VaList> = <Value<VaList>>::default();
     (*ap.borrow_mut()) = VaList::new(args);
     (*aq.borrow_mut()) = (*ap.borrow_mut()).clone();
     let sum1: Value<i32> = Rc::new(RefCell::new(0));
diff --git a/tests/unit/out/refcount/va_arg_forward.rs b/tests/unit/out/refcount/va_arg_forward.rs
index 25929e68..257e60d2 100644
--- a/tests/unit/out/refcount/va_arg_forward.rs
+++ b/tests/unit/out/refcount/va_arg_forward.rs
@@ -20,7 +20,7 @@ pub fn inner_0(count: i32, ap: VaList) -> i32 {
 }
 pub fn outer_1(count: i32, args: &[VaArg]) -> i32 {
     let count: Value<i32> = Rc::new(RefCell::new(count));
-    let ap: Value<VaList> = Rc::new(RefCell::new(<VaList>::default()));
+    let ap: Value<VaList> = <Value<VaList>>::default();
     (*ap.borrow_mut()) = VaList::new(args);
     let result: Value<i32> = Rc::new(RefCell::new(
         ({
diff --git a/tests/unit/out/refcount/va_arg_mixed_int_ptr.rs b/tests/unit/out/refcount/va_arg_mixed_int_ptr.rs
index 4cfaedc3..a8a3aaca 100644
--- a/tests/unit/out/refcount/va_arg_mixed_int_ptr.rs
+++ b/tests/unit/out/refcount/va_arg_mixed_int_ptr.rs
@@ -9,7 +9,7 @@ use std::os::fd::AsFd;
 use std::rc::{Rc, Weak};
 pub fn mixed_args_0(count: i32, args: &[VaArg]) -> i32 {
     let count: Value<i32> = Rc::new(RefCell::new(count));
-    let ap: Value<VaList> = Rc::new(RefCell::new(<VaList>::default()));
+    let ap: Value<VaList> = <Value<VaList>>::default();
     (*ap.borrow_mut()) = VaList::new(args);
     let total: Value<i32> = Rc::new(RefCell::new(0));
     let i: Value<i32> = Rc::new(RefCell::new(0));
diff --git a/tests/unit/out/refcount/va_arg_mixed_types.rs b/tests/unit/out/refcount/va_arg_mixed_types.rs
index c54047df..2dbb4bd2 100644
--- a/tests/unit/out/refcount/va_arg_mixed_types.rs
+++ b/tests/unit/out/refcount/va_arg_mixed_types.rs
@@ -9,7 +9,7 @@ use std::os::fd::AsFd;
 use std::rc::{Rc, Weak};
 pub fn sum_mixed_0(count: i32, args: &[VaArg]) -> i32 {
     let count: Value<i32> = Rc::new(RefCell::new(count));
-    let ap: Value<VaList> = Rc::new(RefCell::new(<VaList>::default()));
+    let ap: Value<VaList> = <Value<VaList>>::default();
     (*ap.borrow_mut()) = VaList::new(args);
     let total: Value<i32> = Rc::new(RefCell::new(0));
     let i: Value<i32> = Rc::new(RefCell::new(0));
diff --git a/tests/unit/out/refcount/va_arg_printf.rs b/tests/unit/out/refcount/va_arg_printf.rs
index 5fe7f0d8..10078dc7 100644
--- a/tests/unit/out/refcount/va_arg_printf.rs
+++ b/tests/unit/out/refcount/va_arg_printf.rs
@@ -17,7 +17,7 @@ pub fn logf_impl_0(fmt: Ptr<u8>, ap: VaList) -> i32 {
 }
 pub fn logf_1(fmt: Ptr<u8>, args: &[VaArg]) -> i32 {
     let fmt: Value<Ptr<u8>> = Rc::new(RefCell::new(fmt));
-    let ap: Value<VaList> = Rc::new(RefCell::new(<VaList>::default()));
+    let ap: Value<VaList> = <Value<VaList>>::default();
     (*ap.borrow_mut()) = VaList::new(args);
     let result: Value<i32> = Rc::new(RefCell::new(
         ({
diff --git a/tests/unit/out/refcount/va_arg_promotion.rs b/tests/unit/out/refcount/va_arg_promotion.rs
index a7065516..7b7f0620 100644
--- a/tests/unit/out/refcount/va_arg_promotion.rs
+++ b/tests/unit/out/refcount/va_arg_promotion.rs
@@ -9,7 +9,7 @@ use std::os::fd::AsFd;
 use std::rc::{Rc, Weak};
 pub fn test_promotions_0(count: i32, args: &[VaArg]) -> i32 {
     let count: Value<i32> = Rc::new(RefCell::new(count));
-    let ap: Value<VaList> = Rc::new(RefCell::new(<VaList>::default()));
+    let ap: Value<VaList> = <Value<VaList>>::default();
     (*ap.borrow_mut()) = VaList::new(args);
     let a: Value<i32> = Rc::new(RefCell::new(((*ap.borrow_mut()).arg::<i32>()).clone()));
     let b: Value<i32> = Rc::new(RefCell::new(((*ap.borrow_mut()).arg::<i32>()).clone()));
@@ -23,7 +23,7 @@ pub fn main() {
     std::process::exit(main_0());
 }
 fn main_0() -> i32 {
-    let x: Value<u8> = Rc::new(RefCell::new(('A' as u8)));
+    let x: Value<u8> = Rc::new(RefCell::new((('A' as i32) as u8)));
     let y: Value<i16> = Rc::new(RefCell::new(10_i16));
     let z: Value<f32> = Rc::new(RefCell::new(3.0E+0));
     assert!(
diff --git a/tests/unit/out/refcount/va_arg_snprintf.rs b/tests/unit/out/refcount/va_arg_snprintf.rs
index fcd28cbf..2d5ee15f 100644
--- a/tests/unit/out/refcount/va_arg_snprintf.rs
+++ b/tests/unit/out/refcount/va_arg_snprintf.rs
@@ -11,7 +11,7 @@ pub fn extract_first_0(buf: Ptr<u8>, size: i32, fmt: Ptr<u8>, args: &[VaArg]) ->
     let buf: Value<Ptr<u8>> = Rc::new(RefCell::new(buf));
     let size: Value<i32> = Rc::new(RefCell::new(size));
     let fmt: Value<Ptr<u8>> = Rc::new(RefCell::new(fmt));
-    let ap: Value<VaList> = Rc::new(RefCell::new(<VaList>::default()));
+    let ap: Value<VaList> = <Value<VaList>>::default();
     (*ap.borrow_mut()) = VaList::new(args);
     let n: Value<i32> = Rc::new(RefCell::new(((*ap.borrow_mut()).arg::<i32>()).clone()));
     let __rhs = ((*n.borrow()) as u8);
@@ -42,6 +42,6 @@ fn main_0() -> i32 {
             extract_first_0(_buf, _size, _fmt, &[65.into()])
         }) == 65)
     );
-    assert!((((*buf.borrow())[(0) as usize] as i32) == (('A' as u8) as i32)));
+    assert!((((*buf.borrow())[(0) as usize] as i32) == ('A' as i32)));
     return 0;
 }
diff --git a/tests/unit/out/refcount/va_arg_two_passes.rs b/tests/unit/out/refcount/va_arg_two_passes.rs
index d5362b99..4f6a25a4 100644
--- a/tests/unit/out/refcount/va_arg_two_passes.rs
+++ b/tests/unit/out/refcount/va_arg_two_passes.rs
@@ -9,7 +9,7 @@ use std::os::fd::AsFd;
 use std::rc::{Rc, Weak};
 pub fn sum_then_product_0(first: i32, args: &[VaArg]) -> i32 {
     let first: Value<i32> = Rc::new(RefCell::new(first));
-    let ap: Value<VaList> = Rc::new(RefCell::new(<VaList>::default()));
+    let ap: Value<VaList> = <Value<VaList>>::default();
     let sum: Value<i32> = Rc::new(RefCell::new((*first.borrow())));
     let product: Value<i32> = Rc::new(RefCell::new((*first.borrow())));
     (*ap.borrow_mut()) = VaList::new(args);
diff --git a/tests/unit/out/unsafe/expr_as_bool.rs b/tests/unit/out/unsafe/expr_as_bool.rs
new file mode 100644
index 00000000..25c79dbb
--- /dev/null
+++ b/tests/unit/out/unsafe/expr_as_bool.rs
@@ -0,0 +1,24 @@
+extern crate libc;
+use libc::*;
+extern crate libcc2rs;
+use libcc2rs::*;
+use std::collections::BTreeMap;
+use std::io::Seek;
+use std::io::{Read, Write};
+use std::os::fd::{AsFd, FromRawFd, IntoRawFd};
+use std::rc::Rc;
+pub fn main() {
+    unsafe {
+        std::process::exit(main_0() as i32);
+    }
+}
+unsafe fn main_0() -> i32 {
+    let mut a: i32 = 0;
+    let mut b: i32 = 0_i32;
+    if ({
+        b = a;
+        b
+    } != 0)
+    {}
+    return 0;
+}
diff --git a/tests/unit/out/unsafe/expr_as_bool_c.rs b/tests/unit/out/unsafe/expr_as_bool_c.rs
new file mode 100644
index 00000000..a136d356
--- /dev/null
+++ b/tests/unit/out/unsafe/expr_as_bool_c.rs
@@ -0,0 +1,54 @@
+extern crate libc;
+use libc::*;
+extern crate libcc2rs;
+use libcc2rs::*;
+use std::collections::BTreeMap;
+use std::io::Seek;
+use std::io::{Read, Write};
+use std::os::fd::{AsFd, FromRawFd, IntoRawFd};
+use std::rc::Rc;
+pub fn main() {
+    unsafe {
+        std::process::exit(main_0() as i32);
+    }
+}
+unsafe fn main_0() -> i32 {
+    let mut a: i32 = 0;
+    let mut b: i32 = 0_i32;
+    if ({
+        b = a;
+        b
+    } != 0)
+    {}
+    'loop_: while ((({
+        b = a;
+        b
+    }) as i32)
+        != (0))
+    {}
+    if (a != 0) {}
+    if ((a) == (b)) {}
+    if ((a) < (b)) {}
+    assert!(((a) == (b)));
+    assert!(
+        (!(({
+            a = b;
+            a
+        }) as i32)
+            != 0)
+    );
+    let mut c: bool = false;
+    c = ({
+        a = b;
+        a
+    } != 0);
+    c = ((({
+        b = a;
+        b
+    }) as i32)
+        != (0));
+    c = (a != 0);
+    c = ((a) == (b));
+    c = ((a) < (b));
+    return 0;
+}
diff --git a/tests/unit/out/unsafe/expr_as_bool_cpp.rs b/tests/unit/out/unsafe/expr_as_bool_cpp.rs
new file mode 100644
index 00000000..a011f145
--- /dev/null
+++ b/tests/unit/out/unsafe/expr_as_bool_cpp.rs
@@ -0,0 +1,54 @@
+extern crate libc;
+use libc::*;
+extern crate libcc2rs;
+use libcc2rs::*;
+use std::collections::BTreeMap;
+use std::io::Seek;
+use std::io::{Read, Write};
+use std::os::fd::{AsFd, FromRawFd, IntoRawFd};
+use std::rc::Rc;
+pub fn main() {
+    unsafe {
+        std::process::exit(main_0() as i32);
+    }
+}
+unsafe fn main_0() -> i32 {
+    let mut a: i32 = 0;
+    let mut b: i32 = 0_i32;
+    if ({
+        b = a;
+        b
+    } != 0)
+    {}
+    'loop_: while ((({
+        b = a;
+        b
+    }) as i32)
+        != (0))
+    {}
+    if (a != 0) {}
+    if ((a) == (b)) {}
+    if ((a) < (b)) {}
+    assert!(((a) == (b)));
+    assert!(
+        !((({
+            a = b;
+            a
+        }) as i32)
+            != 0)
+    );
+    let mut c: bool = false;
+    c = ({
+        a = b;
+        a
+    } != 0);
+    c = ((({
+        b = a;
+        b
+    }) as i32)
+        != (0));
+    c = (a != 0);
+    c = ((a) == (b));
+    c = ((a) < (b));
+    return 0;
+}
diff --git a/tests/unit/out/unsafe/va_arg_concat.rs b/tests/unit/out/unsafe/va_arg_concat.rs
index cddda762..ebd9cdb7 100644
--- a/tests/unit/out/unsafe/va_arg_concat.rs
+++ b/tests/unit/out/unsafe/va_arg_concat.rs
@@ -11,7 +11,7 @@ pub unsafe fn sum_ints_0(mut first: i32, args: &[VaArg]) -> i32 {
     let mut ap: VaList = <VaList>::default();
     let mut total: i32 = first;
     ap = VaList::new(args);
-    let mut val: i32 = <i32>::default();
+    let mut val: i32 = 0_i32;
     'loop_: while ((({
         val = ap.arg::<i32>();
         val
diff --git a/tests/unit/out/unsafe/va_arg_promotion.rs b/tests/unit/out/unsafe/va_arg_promotion.rs
index 5cef927b..7500a36c 100644
--- a/tests/unit/out/unsafe/va_arg_promotion.rs
+++ b/tests/unit/out/unsafe/va_arg_promotion.rs
@@ -24,7 +24,7 @@ pub fn main() {
     }
 }
 unsafe fn main_0() -> i32 {
-    let mut x: u8 = ('A' as u8);
+    let mut x: u8 = (('A' as i32) as u8);
     let mut y: i16 = 10_i16;
     let mut z: f32 = 3.0E+0;
     assert!(
diff --git a/tests/unit/out/unsafe/va_arg_snprintf.rs b/tests/unit/out/unsafe/va_arg_snprintf.rs
index 38ccf04e..40d91d60 100644
--- a/tests/unit/out/unsafe/va_arg_snprintf.rs
+++ b/tests/unit/out/unsafe/va_arg_snprintf.rs
@@ -25,7 +25,7 @@ pub fn main() {
     }
 }
 unsafe fn main_0() -> i32 {
-    let mut buf: [u8; 64] = [<u8>::default(); 64];
+    let mut buf: [u8; 64] = [0_u8; 64];
     assert!(
         ((unsafe {
             let _buf: *mut u8 = buf.as_mut_ptr();
@@ -43,6 +43,6 @@ unsafe fn main_0() -> i32 {
             extract_first_0(_buf, _size, _fmt, &[65.into()])
         }) == (65))
     );
-    assert!(((buf[(0) as usize] as i32) == (('A' as u8) as i32)));
+    assert!(((buf[(0) as usize] as i32) == ('A' as i32)));
     return 0;
 }
diff --git a/tests/unit/out/unsafe/va_arg_two_passes.rs b/tests/unit/out/unsafe/va_arg_two_passes.rs
index 0ebe33ca..93f2df7c 100644
--- a/tests/unit/out/unsafe/va_arg_two_passes.rs
+++ b/tests/unit/out/unsafe/va_arg_two_passes.rs
@@ -12,7 +12,7 @@ pub unsafe fn sum_then_product_0(mut first: i32, args: &[VaArg]) -> i32 {
     let mut sum: i32 = first;
     let mut product: i32 = first;
     ap = VaList::new(args);
-    let mut val: i32 = <i32>::default();
+    let mut val: i32 = 0_i32;
     'loop_: while ((({
         val = ap.arg::<i32>();
         val
diff --git a/tests/unit/va_arg_chain.c b/tests/unit/va_arg_chain.c
index 5b627395..c7233384 100644
--- a/tests/unit/va_arg_chain.c
+++ b/tests/unit/va_arg_chain.c
@@ -8,9 +8,7 @@ int extract_nth(int n, va_list ap) {
   return va_arg(ap, int);
 }
 
-int middle_layer(int n, va_list ap) {
-  return extract_nth(n, ap);
-}
+int middle_layer(int n, va_list ap) { return extract_nth(n, ap); }
 
 int top_level(int n, ...) {
   va_list ap;
diff --git a/tests/unit/va_arg_promotion.c b/tests/unit/va_arg_promotion.c
index 7b74bbef..54b38526 100644
--- a/tests/unit/va_arg_promotion.c
+++ b/tests/unit/va_arg_promotion.c
@@ -6,11 +6,11 @@ int test_promotions(int count, ...) {
   va_start(ap, count);
 
   // char and short are promoted to int by the caller
-  int a = va_arg(ap, int);   // was passed as char 'A' (65)
-  int b = va_arg(ap, int);   // was passed as short 10
+  int a = va_arg(ap, int); // was passed as char 'A' (65)
+  int b = va_arg(ap, int); // was passed as short 10
 
   // float is promoted to double by the caller
-  double c = va_arg(ap, double);  // was passed as float 3.0
+  double c = va_arg(ap, double); // was passed as float 3.0
 
   va_end(ap);
 
diff --git a/tests/unit/va_arg_struct_ctx.c b/tests/unit/va_arg_struct_ctx.cpp
similarity index 100%
rename from tests/unit/va_arg_struct_ctx.c
rename to tests/unit/va_arg_struct_ctx.cpp