I guess main can return Results now.

src/bin/accounting.rs

@@ -4,7 +4,7 @@ use std::env;
 use std::fs;
 use std::str::FromStr;
 
-fn real_main() -> Result<(), TopLevelError> {
+fn main() -> Result<(), TopLevelError> {
     let mut numbers = Vec::new();
 
     for argument in env::args().skip(1) {
@@ -119,9 +119,3 @@ fn next_target(low_index: usize, high_index: usize, avoid: &[usize]) -> Option<u
 
     None
 }
-
-fn main() {
-    if let Err(e) = real_main() {
-        eprintln!("ERROR: {}", e);
-    }
-}

src/bin/baggage.rs

@@ -186,7 +186,7 @@ fn parse_rule_item(input0: &str) -> nom::IResult<&str, Rule> {
     Ok((input6, Rule { count, bag }))
 }
 
-fn real_main() -> Result<(), TopLevelError> {
+fn main() -> Result<(), TopLevelError> {
     let mut rules = RuleSet::empty();
 
     for argument in env::args().skip(1) {
@@ -212,9 +212,3 @@ fn real_main() -> Result<(), TopLevelError> {
 
     Ok(())
 }
-
-fn main() {
-    if let Err(e) = real_main() {
-        eprintln!("ERROR: {}", e);
-    }
-}

src/bin/boarding_pass.rs

@@ -119,7 +119,7 @@ fn example_boarding_passes() {
     );
 }
 
-fn real_main() -> Result<(), TopLevelError> {
+fn main() -> Result<(), TopLevelError> {
     let mut seats = BTreeSet::new();
     let mut highest_id = 0;
 
@@ -148,9 +148,3 @@ fn real_main() -> Result<(), TopLevelError> {
 
     Err(TopLevelError::NoSolutionFound)
 }
-
-fn main() {
-    if let Err(e) = real_main() {
-        eprintln!("ERROR: {}", e);
-    }
-}

src/bin/customs_form.rs

@@ -3,7 +3,7 @@ use std::collections::BTreeSet;
 use std::env;
 use std::fs;
 
-fn real_main() -> Result<(), TopLevelError> {
+fn main() -> Result<(), TopLevelError> {
     let mut customs_forms_any = Vec::new();
     let mut customs_forms_all = Vec::new();
 
@@ -74,9 +74,3 @@ fn every_seat() -> BTreeSet<char> {
 
     result
 }
-
-fn main() {
-    if let Err(e) = real_main() {
-        eprintln!("ERROR: {}", e);
-    }
-}

src/bin/machine.rs

@@ -154,7 +154,7 @@ impl Iterator for VariantGenerator {
     }
 }
 
-fn real_main() -> Result<(), TopLevelError> {
+fn main() -> Result<(), TopLevelError> {
     let filename = env::args().skip(1).next().expect("No file argument given.");
     let contents = fs::read_to_string(filename)?;
     let machine = Machine::from_str(&contents)?;
@@ -178,9 +178,3 @@ fn real_main() -> Result<(), TopLevelError> {
 
     Ok(())
 }
-
-fn main() {
-    if let Err(e) = real_main() {
-        eprintln!("ERROR: {}", e);
-    }
-}

src/bin/passport.rs

@@ -137,7 +137,7 @@ fn valid_year_range(field: &Option<String>, start: u64, end: u64) -> bool {
     true
 }
 
-fn real_main() -> Result<(), TopLevelError> {
+fn main() -> Result<(), TopLevelError> {
     let mut passports = Vec::new();
 
     for argument in env::args().skip(1) {
@@ -170,9 +170,3 @@ fn real_main() -> Result<(), TopLevelError> {
 
     Ok(())
 }
-
-fn main() {
-    if let Err(e) = real_main() {
-        eprintln!("ERROR: {}", e);
-    }
-}

src/bin/password_check.rs

@@ -64,7 +64,7 @@ impl PasswordData {
     }
 }
 
-fn real_main() -> Result<(), TopLevelError> {
+fn main() -> Result<(), TopLevelError> {
     let mut good_items_interpretation1 = 0u64;
     let mut good_items_interpretation2 = 0u64;
 
@@ -97,9 +97,3 @@ fn real_main() -> Result<(), TopLevelError> {
 
     Ok(())
 }
-
-fn main() {
-    if let Err(e) = real_main() {
-        eprintln!("ERROR: {}", e);
-    }
-}

src/bin/tobaggan.rs

@@ -49,7 +49,7 @@ fn trail_for_slope(map: &Map<Square>, run: usize, fall: usize) -> Encounters {
     encounters
 }
 
-fn real_main() -> Result<(), TopLevelError> {
+fn main() -> Result<(), TopLevelError> {
     let mut maybe_map = None;
 
     for argument in env::args().skip(1) {
@@ -91,9 +91,3 @@ fn real_main() -> Result<(), TopLevelError> {
 
     Ok(())
 }
-
-fn main() {
-    if let Err(e) = real_main() {
-        eprintln!("ERROR: {}", e);
-    }
-}