diff --git a/Cargo.lock b/Cargo.lock
index 132bb83..f6a4c02 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -711,7 +711,7 @@ dependencies = [
  "cc 1.0.47 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.66 (registry+https://github.com/rust-lang/crates.io-index)",
  "pkg-config 0.3.17 (registry+https://github.com/rust-lang/crates.io-index)",
- "vcpkg 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "vcpkg 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -794,6 +794,20 @@ dependencies = [
  "libc 0.2.66 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "pledge-example-2015"
+version = "0.0.0"
+dependencies = [
+ "pledge 0.3.1",
+]
+
+[[package]]
+name = "pledge-example-2018"
+version = "0.0.0"
+dependencies = [
+ "pledge 0.3.1",
+]
+
 [[package]]
 name = "pledge-variants"
 version = "0.0.0"
@@ -1521,7 +1535,7 @@ dependencies = [
 
 [[package]]
 name = "vcpkg"
-version = "0.2.7"
+version = "0.2.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
@@ -1764,7 +1778,7 @@ dependencies = [
 "checksum url 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "75b414f6c464c879d7f9babf951f23bc3743fb7313c081b2e6ca719067ea9d61"
 "checksum utf-8 0.7.5 (registry+https://github.com/rust-lang/crates.io-index)" = "05e42f7c18b8f902290b009cde6d651262f956c98bc51bca4cd1d511c9cd85c7"
 "checksum uuid 0.7.4 (registry+https://github.com/rust-lang/crates.io-index)" = "90dbc611eb48397705a6b0f6e917da23ae517e4d127123d2cf7674206627d32a"
-"checksum vcpkg 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)" = "33dd455d0f96e90a75803cfeb7f948768c08d70a6de9a8d2362461935698bf95"
+"checksum vcpkg 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "3fc439f2794e98976c88a2a2dafce96b930fe8010b0a256b3c2199a773933168"
 "checksum version_check 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "914b1a6776c4c929a602fafd8bc742e06365d4bcbe48c30f9cca5824f70dc9dd"
 "checksum version_check 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)" = "078775d0255232fb988e6fccf26ddc9d1ac274299aaedcedce21c6f72cc533ce"
 "checksum want 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b6395efa4784b027708f7451087e647ec73cc74f5d9bc2e418404248d679a230"
diff --git a/Cargo.toml b/Cargo.toml
index 5bcb301..497b164 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -10,7 +10,7 @@ keywords = ["openbsd", "binding", "security"]
 license = "MIT"
 
 [workspace]
-members = ["variants"]
+members = ["variants", "example-2015", "example-2018"]
 
 [dependencies]
 libc = "0.2"
diff --git a/README.md b/README.md
index fb3944d..c0195cb 100644
--- a/README.md
+++ b/README.md
@@ -7,77 +7,71 @@ A Rust binding to OpenBSD's pledge(2) interface.
 
 ## Usage
 
-    #[macro_use] extern crate pledge;
-    use pledge::{pledge, Promise, ToPromiseString};
+    /* Rust 2015 only */ #[macro_use] extern crate pledge;
+    /* Rust 2018 only */ use pledge::{pledge, pledge_promises, pledge_execpromises};
 
     fn foo() {
         // make both promises and execpromises
-        match pledge![Stdio Proc Exec, Stdio Tty] {
-            Err(_) => println!("Failed to pledge"),
-            _ => ()
-        }
+        pledge![Stdio Proc Exec, Stdio Tty].unwrap();
 
         // make promises only
-        match pledge_promises[Stdio Exec] {
-            Err(_) => println!("Failed to pledge"),
-            _ => ()
-        }
+        pledge_promises![Stdio Exec].unwrap();
 
         // make execpromises only
-        match pledge_execpromises[Stdio] {
-            Err(_) => println!("Failed to pledge"),
-            _ => ()
-        }
+        pledge_execpromises![Stdio].unwrap();
     }
 
-This is equivalent to:
+This is roughly equivalent to:
 
-    extern crate pledge;
+    /* Rust 2015 only */ extern crate pledge;
     use pledge::{pledge, Promise, ToPromiseString};
 
     fn foo() {
         // make both promises and execpromises
         let promises = vec![Promise::Stdio, Promise::Proc, Promise::Exec];
         let execpromises = vec![Promise::Stdio, Promise::Tty];
-        match pledge(&*promises.to_promise_string(), &*execpromises.to_promise_string()) {
-            Err(_) => println!("Failed to pledge"),
-            _ => ()
-        }
+        pledge(&*promises.to_promise_string(), &*execpromises.to_promise_string()).unwrap();
 
         // make promises only
         let promises = vec![Promise::Stdio, Promise::Exec];
-        match pledge(&*promises.to_promise_string(), None) {
-            Err(_) => println!("Failed to pledge"),
-            _ => ()
-        }
+        pledge(&*promises.to_promise_string(), None).unwrap();
 
         // make execpromises only
         let execpromises = vec![Promise::Stdio];
-        match pledge(None, &*execpromises.to_promise_string()) {
-            Err(_) => println!("Failed to pledge"),
-            _ => ()
-        }
+        pledge(None, &*execpromises.to_promise_string()).unwrap();
     }
 
 You may also provide promises directly as a string:
 
+    /* Rust 2015 only */ extern crate pledge;
     use pledge::pledge;
 
     fn foo() {
         // make both promises and execpromises
-        if pledge("stdio proc exec", "stdio tty").is_err() {
-            panic!("Failed to pledge");
-        }
+        pledge("stdio proc exec", "stdio tty").unwrap();
 
         // make promises only
-        if pledge("stdio exec", None).is_err() {
-            panic!("Failed to pledge");
-        }
+        pledge("stdio exec", None).unwrap();
 
         // make execpromises only
-        if pledge(None, "stdio").is_err() {
-            panic!("Failed to pledge");
-        }
+        pledge(None, "stdio").unwrap();
+    }
+
+All of these will yield `pledge::Error::UnsupportedPlatform` on platforms that
+don’t support pledge(2). You can use `pledge::Error::ignore_platform` to ignore
+that variant and make your program portable to those platforms:
+
+    /* Rust 2015 only */ extern crate pledge;
+    /* Rust 2018 only */ use pledge::pledge_promises;
+
+    fn foo() {
+        ...
+
+        pledge_promises![Stdio Exec]
+            .or_else(pledge::Error::ignore_platform)
+            .unwrap();
+
+        ...
     }
 
 ## Compatibility
@@ -91,7 +85,7 @@ where the second parameter sets a whitelist of permitted paths.
 
 To migrate your code from older versions:
 
-* change `pledge![P, Q, R]` call sites to `pledge_promises![P, Q, R]`
+* change `pledge![P, Q, R]` call sites to `pledge_promises![P Q R]`
 * change `pledge("p q r")` call sites to `pledge("p q r", None)`
 * change `pledge_with_paths(promises, paths)` to `pledge(promises)`
 * update usage of renamed `Promise` variants (e.g. `MCast` → `Mcast`)
diff --git a/example-2015/.gitignore b/example-2015/.gitignore
new file mode 100644
index 0000000..b83d222
--- /dev/null
+++ b/example-2015/.gitignore
@@ -0,0 +1 @@
+/target/
diff --git a/example-2015/Cargo.toml b/example-2015/Cargo.toml
new file mode 100644
index 0000000..6a4803b
--- /dev/null
+++ b/example-2015/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "pledge-example-2015"
+version = "0.0.0"
+authors = ["Andrew Aldridge <i80and@foxquill.com>", "Delan Azabani <delan@azabani.com>"]
+edition = "2015"
+publish = false
+
+[dependencies.pledge]
+path = ".."
diff --git a/example-2015/rustfmt.toml b/example-2015/rustfmt.toml
new file mode 100644
index 0000000..e69de29
diff --git a/example-2015/src/main.rs b/example-2015/src/main.rs
new file mode 100644
index 0000000..74a61e8
--- /dev/null
+++ b/example-2015/src/main.rs
@@ -0,0 +1,9 @@
+#[macro_use]
+extern crate pledge;
+
+fn main() {
+    pledge_promises![Stdio]
+        .or_else(pledge::Error::ignore_platform)
+        .unwrap();
+    println!("Hello, world!");
+}
diff --git a/example-2018/.gitignore b/example-2018/.gitignore
new file mode 100644
index 0000000..b83d222
--- /dev/null
+++ b/example-2018/.gitignore
@@ -0,0 +1 @@
+/target/
diff --git a/example-2018/Cargo.toml b/example-2018/Cargo.toml
new file mode 100644
index 0000000..e7e69b9
--- /dev/null
+++ b/example-2018/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "pledge-example-2018"
+version = "0.0.0"
+authors = ["Andrew Aldridge <i80and@foxquill.com>", "Delan Azabani <delan@azabani.com>"]
+edition = "2018"
+publish = false
+
+[dependencies.pledge]
+path = ".."
diff --git a/example-2018/rustfmt.toml b/example-2018/rustfmt.toml
new file mode 100644
index 0000000..e69de29
diff --git a/example-2018/src/main.rs b/example-2018/src/main.rs
new file mode 100644
index 0000000..fcd76fd
--- /dev/null
+++ b/example-2018/src/main.rs
@@ -0,0 +1,8 @@
+use pledge::pledge_promises;
+
+fn main() {
+    pledge_promises![Stdio]
+        .or_else(pledge::Error::ignore_platform)
+        .unwrap();
+    println!("Hello, world!");
+}
diff --git a/src/lib.rs b/src/lib.rs
index 208b9e4..7a0b116 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -12,6 +12,15 @@ pub enum Error {
     Other(c_int),
 }
 
+impl Error {
+    pub fn ignore_platform(self) -> Result<(), Self> {
+        match self {
+            Error::UnsupportedPlatform => Ok(()),
+            x => Err(x),
+        }
+    }
+}
+
 impl fmt::Display for Error {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match *self {
@@ -68,14 +77,14 @@ macro_rules! pledge {
             let mut promises = Vec::new();
             let mut execpromises = Vec::new();
             $(
-                promises.push(Promise::$promises);
+                promises.push($crate::Promise::$promises);
             )*
             $(
-                execpromises.push(Promise::$execpromises);
+                execpromises.push($crate::Promise::$execpromises);
             )*
-            let promises = promises.to_promise_string();
-            let execpromises = execpromises.to_promise_string();
-            pledge(&*promises, &*execpromises)
+            let promises = $crate::ToPromiseString::to_promise_string(&*promises);
+            let execpromises = $crate::ToPromiseString::to_promise_string(&*execpromises);
+            $crate::pledge(&*promises, &*execpromises)
         }
     };
 }
@@ -86,10 +95,10 @@ macro_rules! pledge_promises {
         {
             let mut promises = Vec::new();
             $(
-                promises.push(Promise::$promises);
+                promises.push($crate::Promise::$promises);
             )*
-            let promises = promises.to_promise_string();
-            pledge(&*promises, None)
+            let promises = $crate::ToPromiseString::to_promise_string(&*promises);
+            $crate::pledge(&*promises, None)
         }
     };
 }
@@ -100,10 +109,10 @@ macro_rules! pledge_execpromises {
         {
             let mut execpromises = Vec::new();
             $(
-                execpromises.push(Promise::$execpromises);
+                execpromises.push($crate::Promise::$execpromises);
             )*
-            let execpromises = execpromises.to_promise_string();
-            pledge(None, &*execpromises)
+            let execpromises = $crate::ToPromiseString::to_promise_string(&*execpromises);
+            $crate::pledge(None, &*execpromises)
         }
     };
 }