Bumped release to 0.2.13. assertion macros now use core::panic (#14)

* Bumped release to 0.2.13. assertion macros now use `core::panic` `core::panic` changed to allow passing a non-literal `&'static str` argument after writing the const_format assertion macros. Updated changelog * Fixed bug caused by use of respan macro * Delete .travis.yml
rodrimati1992 · Jan 13, 2021 · 2946cfe · 2946cfe
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diff --git a/.travis.yml b/.travis.yml
diff --git a/Changelog.md b/Changelog.md
@@ -2,6 +2,10 @@ This is the changelog,summarising changes in each version(some minor changes may
 
 # 0.2 
 
+### 0.2.13
+
+Fixed the assertion macros not to use `std::panic`, using `core::panic` instead, since `core::panic` changed to allow passing a non-literal `&'static str` argument.
+
 ### 0.2.11
 
 Fixed the documentation in case that the https://github.com/rust-lang/rust/pull/80243 

diff --git a/README.md b/README.md
@@ -261,9 +261,8 @@ This implicitly uses the `syn` crate, so clean compiles take a bit longer than w
 
 - "assert": implies the "fmt" feature,
 enables the assertion macros.<br>
-This is a separate cargo feature because:
-    - It uses nightly Rust features that are less stable than the "fmt" feature does.<br>
-    - It requires the `std` crate, because `core::panic` requires a string literal argument.
+This is a separate cargo feature because 
+it uses nightly Rust features that are less stable than the "fmt" feature does.
 
 - "constant_time_as_str": implies the "fmt" feature.
 An optimization that requires a few additional nightly features,
@@ -283,9 +282,6 @@ This requires a nightly Rust compiler.
 
 `const_format` is `#![no_std]`, it can be used anywhere Rust can be used.
 
-Caveat: The opt-in "assert" feature uses the `std::panic` macro to panic,
-as of 2020-09-06 `core::panic` requires the argument to be a literal.
-
 # Minimum Supported Rust Version
 
 `const_format` requires Rust 1.46.0, because it uses looping an branching in const contexts.

diff --git a/const_format/Cargo.toml b/const_format/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "const_format"
-version = "0.2.12"
+version = "0.2.13"
 authors = ["rodrimati1992 <[email protected]>"]
 edition = "2018"
 license = "Zlib"

diff --git a/const_format/src/lib.rs b/const_format/src/lib.rs
@@ -249,9 +249,8 @@
 //!
 //! - "assert": implies the "fmt" feature,
 //! enables the assertion macros.<br>
-//! This is a separate cargo feature because:
-//!     - It uses nightly Rust features that are less stable than the "fmt" feature does.<br>
-//!     - It requires the `std` crate, because `core::panic` requires a string literal argument.
+//! This is a separate cargo feature because
+//! it uses nightly Rust features that are less stable than the "fmt" feature does.<br>
 //!
 //! - "constant_time_as_str": implies the "fmt" feature.
 //! An optimization that requires a few additional nightly features,
@@ -339,10 +338,6 @@
 
 include! {"const_debug_derive.rs"}
 
-// Only used for panicking. Once panicking works without std, I'll remove this.
-#[cfg(feature = "assert")]
-extern crate std;
-
 #[macro_use]
 mod macros;
 

diff --git a/const_format/src/macros/assertions.rs b/const_format/src/macros/assertions.rs
@@ -13,8 +13,6 @@ macro_rules! with_shared_docs {(
     ///
     /// This macro requires the "assert" feature to be exported,
     /// because it uses some nightly Rust features.<br>
-    /// It uses `std::panic` for panicking due to an unforseen limitation
-    /// in `core::panic`, which doesn't allow passing non-literal strings at compile-time.
     ///
     $(#[$before_syntax])*
     /// # Syntax

diff --git a/const_format/src/macros/fmt_macros.rs b/const_format/src/macros/fmt_macros.rs
@@ -322,64 +322,54 @@ macro_rules! __concatc_expr {
 
 #[doc(hidden)]
 #[macro_export]
-macro_rules! __concatc_inner{
-    ($debug_fmt_fn:ident, $cond:expr, $($span:tt)*)=>{{
-        $crate::pmr::respan_to!{($($span)*) {
-            const fn len_nhpmwyd3nj() -> usize {
-                if $cond {
-                    let mut strlen = __cf_osRcTFl4A::pmr::ComputeStrLength::new();
-                    let fmt = strlen.make_formatter(__cf_osRcTFl4A::FormattingFlags::NEW);
-                    match $debug_fmt_fn(fmt) {
-                        __cf_osRcTFl4A::pmr::Ok(()) => strlen.len(),
-                        __cf_osRcTFl4A::pmr::Err(_) => 0,
-                    }
-                } else {
-                    0
+macro_rules! __concatc_inner {
+    ($debug_fmt_fn:ident, $cond:expr, $($span:tt)*) => {{
+        const fn len_nhpmwyd3nj() -> usize {
+            if $cond {
+                let mut strlen = __cf_osRcTFl4A::pmr::ComputeStrLength::new();
+                let fmt = strlen.make_formatter(__cf_osRcTFl4A::FormattingFlags::NEW);
+                match $debug_fmt_fn(fmt) {
+                    __cf_osRcTFl4A::pmr::Ok(()) => strlen.len(),
+                    __cf_osRcTFl4A::pmr::Err(_) => 0,
                 }
+            } else {
+                0
             }
+        }
 
-            const LEN_NHPMWYD3NJA: usize = len_nhpmwyd3nj();
+        const LEN_NHPMWYD3NJA: usize = len_nhpmwyd3nj();
 
-            const fn str_writer_nhpmwyd3nja(
-            )-> __cf_osRcTFl4A::msg::ErrorTupleAndStrWriter<[u8; LEN_NHPMWYD3NJA]> {
-                let mut writer = __cf_osRcTFl4A::pmr::StrWriter::new([0; LEN_NHPMWYD3NJA]);
-                let error = if $cond {
-                    $debug_fmt_fn(
-                        __cf_osRcTFl4A::pmr::Formatter::from_sw(
-                            &mut writer,
-                            __cf_osRcTFl4A::FormattingFlags::NEW,
-                        )
-                    )
-                } else {
-                    __cf_osRcTFl4A::pmr::Ok(())
-                };
+        const fn str_writer_nhpmwyd3nja(
+        ) -> __cf_osRcTFl4A::msg::ErrorTupleAndStrWriter<[u8; LEN_NHPMWYD3NJA]> {
+            let mut writer = __cf_osRcTFl4A::pmr::StrWriter::new([0; LEN_NHPMWYD3NJA]);
+            let error = if $cond {
+                $debug_fmt_fn(__cf_osRcTFl4A::pmr::Formatter::from_sw(
+                    &mut writer,
+                    __cf_osRcTFl4A::FormattingFlags::NEW,
+                ))
+            } else {
+                __cf_osRcTFl4A::pmr::Ok(())
+            };
 
-                __cf_osRcTFl4A::msg::ErrorTupleAndStrWriter{
-                    error: __cf_osRcTFl4A::msg::ErrorTuple::new(error, &writer),
-                    writer,
-                }
+            __cf_osRcTFl4A::msg::ErrorTupleAndStrWriter {
+                error: __cf_osRcTFl4A::msg::ErrorTuple::new(error, &writer),
+                writer,
             }
+        }
 
-            const STR_WRITER_NHPMWYD3NJA:
-                &__cf_osRcTFl4A::msg::ErrorTupleAndStrWriter<[u8; LEN_NHPMWYD3NJA]>=
-                &str_writer_nhpmwyd3nja();
+        const STR_WRITER_NHPMWYD3NJA: &__cf_osRcTFl4A::msg::ErrorTupleAndStrWriter<
+            [u8; LEN_NHPMWYD3NJA],
+        > = &str_writer_nhpmwyd3nja();
 
-            const _: __cf_osRcTFl4A::msg::Ok =
-                <
-                    <
-                        __cf_osRcTFl4A::msg::ErrorPicker<
-                            [(); STR_WRITER_NHPMWYD3NJA.error.error_variant],
-                            [(); STR_WRITER_NHPMWYD3NJA.error.capacity]
-                        >
-                        as __cf_osRcTFl4A::msg::ErrorAsType
-                    >::Type
-                >::NEW;
+        const _: __cf_osRcTFl4A::msg::Ok = <<__cf_osRcTFl4A::msg::ErrorPicker<
+            [(); STR_WRITER_NHPMWYD3NJA.error.error_variant],
+            [(); STR_WRITER_NHPMWYD3NJA.error.capacity],
+        > as __cf_osRcTFl4A::msg::ErrorAsType>::Type>::NEW;
 
-            const STR_NHPMWYD3NJA: &str =
-                __cf_osRcTFl4A::strwriter_as_str!(&STR_WRITER_NHPMWYD3NJA.writer);
+        const STR_NHPMWYD3NJA: &str =
+            __cf_osRcTFl4A::strwriter_as_str!(&STR_WRITER_NHPMWYD3NJA.writer);
 
-            STR_NHPMWYD3NJA
-        }}
+        STR_NHPMWYD3NJA
     }};
 }
 

diff --git a/const_format/src/panicking.rs b/const_format/src/panicking.rs
@@ -1,21 +1,21 @@
-pub trait Message {
-    const COND: bool;
-    const MSG: &'static str;
-    const PANIC: usize = <Self as PanicIf>::PANIC;
-}
-
-pub trait PanicIf: Message {
-    const PANIC: usize;
-}
-
 macro_rules! panic_ {
     ($($span:tt)*)=> {crate::pmr::respan_to!{($($span)*)
+        pub trait Message {
+            const COND: bool;
+            const MSG: &'static str;
+            const PANIC: usize = <Self as PanicIf>::PANIC;
+        }
+
+        pub trait PanicIf: Message {
+            const PANIC: usize;
+        }
+
         impl<T> crate::panicking::PanicIf for T
         where
             T: ?Sized + crate::panicking::Message,
         {
             const PANIC: usize = {
-                use ::std::panic as do_not_show_this_code_rustc;
+                use ::core::panic as do_not_show_this_code_rustc;
 
                 let secret = T::MSG;
                 if T::COND {
@@ -48,10 +48,5 @@ macro_rules! assert_with_str {
         }
 
         const _: usize = <__PanicWithStr as $crate::panicking::Message>::PANIC;
-
-        // Errors about infinite loops show up above the panic.
-        if $cond {
-            loop {}
-        }
     }};
 }
diff --git a/print_errors/src/using_assertc_macros.rs b/print_errors/src/using_assertc_macros.rs
@@ -16,3 +16,7 @@ assertc_eq!((), (), "{}");
 assertc_eq!((), (), "{}", foo = "", 100u8);
 
 assertc_eq!(0u8, 1u8, "{}", 0);
+
+assertc_eq!(0u8, 1u8, "{}", 0u8);
+
+assertc!(2 + 2 == 5, "{}", 0u8);