diff --git a/.gitignore b/.gitignore
index 01c49fd..b934256 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@ target
 *.zip
 rustfmt.toml
 **/*.rs.bk
+csmith
diff --git a/src/ir/dtype.rs b/src/ir/dtype.rs
index 1d89086..f769483 100644
--- a/src/ir/dtype.rs
+++ b/src/ir/dtype.rs
@@ -86,9 +86,11 @@ pub enum Dtype {
     /// TODO(document)
     Struct {
         /// TODO(document)
+        // FIXME: Why is this an option?
         name: Option<String>,
 
         /// TODO(document)
+        // FIXME: Just use vec for empty set of fields, no need for option?
         fields: Option<Vec<Named<Dtype>>>,
 
         /// TODO(document)
diff --git a/src/ir/visualize.rs b/src/ir/visualize.rs
index 6ea095f..9b6286c 100644
--- a/src/ir/visualize.rs
+++ b/src/ir/visualize.rs
@@ -3,7 +3,7 @@
 use std::collections::HashMap;
 
 use crate::ir::*;
-use crate::{some_or, Translate};
+use crate::Translate;
 
 #[derive(Default, Debug)]
 pub struct Visualizer {
@@ -29,7 +29,9 @@ impl Translate<TranslationUnit> for Visualizer {
                     signature,
                     definition,
                 } => {
-                    let definition = some_or!(definition, continue);
+                    let Some(definition) = definition else {
+                        continue;
+                    };
                     let subgraph = self.translate_function(name, signature, definition)?;
                     subgraphs.push(subgraph);
                 }
@@ -41,7 +43,9 @@ impl Translate<TranslationUnit> for Visualizer {
         // Add edges between subgraphs
         for (name, decl) in &source.decls {
             if let Declaration::Function { definition, .. } = decl {
-                let definition = some_or!(definition, continue);
+                let Some(definition) = definition else {
+                    continue;
+                };
 
                 for (bid, block) in &definition.blocks {
                     for (iid, instruction) in block.instructions.iter().enumerate() {
diff --git a/src/ir/write_ir.rs b/src/ir/write_ir.rs
index 77c1777..b20a328 100644
--- a/src/ir/write_ir.rs
+++ b/src/ir/write_ir.rs
@@ -2,7 +2,6 @@ use std::io::{Result, Write};
 
 use crate::ir::*;
 use crate::write_base::*;
-use crate::*;
 
 impl WriteLine for TranslationUnit {
     fn write_line(&self, indent: usize, write: &mut dyn Write) -> Result<()> {
@@ -36,14 +35,16 @@ impl WriteLine for TranslationUnit {
         }
 
         for (name, decl) in &self.decls {
-            let _ = some_or!(decl.get_variable(), continue);
-            (name, decl).write_line(indent, write)?;
+            if decl.get_variable().is_some() {
+                (name, decl).write_line(indent, write)?;
+            }
         }
 
         for (name, decl) in &self.decls {
-            let _ = some_or!(decl.get_function(), continue);
-            writeln!(write)?;
-            (name, decl).write_line(indent, write)?;
+            if decl.get_function().is_some() {
+                writeln!(write)?;
+                (name, decl).write_line(indent, write)?;
+            }
         }
 
         Ok(())
diff --git a/src/irgen/mod.rs b/src/irgen/mod.rs
index a7746c4..d32ad9f 100644
--- a/src/irgen/mod.rs
+++ b/src/irgen/mod.rs
@@ -725,7 +725,7 @@ fn name_of_params_from_derived_declarators(
 
 #[inline]
 fn name_of_parameter_declaration(parameter_declaration: &ParameterDeclaration) -> Option<String> {
-    let declarator = some_or!(parameter_declaration.declarator.as_ref(), return None);
+    let declarator = parameter_declaration.declarator.as_ref()?;
     Some(name_of_declarator(&declarator.node))
 }
 
diff --git a/src/opt/mod.rs b/src/opt/mod.rs
index cb3c7ad..ed53684 100644
--- a/src/opt/mod.rs
+++ b/src/opt/mod.rs
@@ -77,7 +77,7 @@ where
     T: Optimize<ir::FunctionDefinition>,
 {
     fn optimize(&mut self, code: &mut ir::Declaration) -> bool {
-        let (_fsig, fdef) = some_or!(code.get_function_mut(), return false);
+        let (_, fdef) = some_or!(code.get_function_mut(), return false);
         let fdef = some_or!(fdef, return false);
         self.inner.optimize(fdef)
     }
diff --git a/src/utils.rs b/src/utils.rs
index 4088ad2..e9fe130 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -1,14 +1,3 @@
-#[macro_export]
-/// Ok or executing the given expression.
-macro_rules! ok_or {
-    ($e:expr_2021, $err:expr_2021) => {{
-        match $e {
-            Ok(r) => r,
-            Err(_) => $err,
-        }
-    }};
-}
-
 #[macro_export]
 /// Some or executing the given expression.
 macro_rules! some_or {
diff --git a/tests/test_examples.rs b/tests/test_examples.rs
index dc541a7..6ef08cd 100644
--- a/tests/test_examples.rs
+++ b/tests/test_examples.rs
@@ -8,8 +8,7 @@ where
     F: Fn(&Path),
 {
     let dir = path.read_dir().expect("read_dir call failed");
-    for entry in dir {
-        let entry = ok_or!(entry, continue);
+    for entry in dir.filter_map(Result::ok) {
         let path = entry.path();
 
         if !(path.is_file() && path.extension() == Some(ext)) {
@@ -24,8 +23,7 @@ where
 fn test_opt_between_dirs<O: Optimize<ir::TranslationUnit>>(from: &Path, to: &Path, opt: &mut O) {
     let from_dir = from.read_dir().expect("read_dir call failed");
 
-    for entry in from_dir {
-        let entry = ok_or!(entry, continue);
+    for entry in from_dir.filter_map(Result::ok) {
         let from_file_path = entry.path();
 
         if !(from_file_path.is_file() && from_file_path.extension() == Some(OsStr::new("ir"))) {
@@ -34,7 +32,7 @@ fn test_opt_between_dirs<O: Optimize<ir::TranslationUnit>>(from: &Path, to: &Pat
 
         let file_name = from_file_path
             .strip_prefix(from)
-            .expect("`from_file _path` must have file name");
+            .expect("`from_file_path` must have file name");
         let to_file_path = to.join(file_name);
 
         assert!(from_file_path.is_file());