1 files changed, 152 insertions, 0 deletions
diff --git a/Utils/src/ERRNO.cs b/Utils/src/ERRNO.cs
new file mode 100644
index 0000000..c3c61de
--- /dev/null
+++ b/Utils/src/ERRNO.cs
@@ -0,0 +1,152 @@
+/*
+* Copyright (c) 2022 Vaughn Nugent
+* 
+* Library: VNLib
+* Package: VNLib.Utils
+* File: ERRNO.cs 
+*
+* ERRNO.cs is part of VNLib.Utils which is part of the larger 
+* VNLib collection of libraries and utilities.
+*
+* VNLib.Utils is free software: you can redistribute it and/or modify 
+* it under the terms of the GNU General Public License as published
+* by the Free Software Foundation, either version 2 of the License,
+* or (at your option) any later version.
+*
+* VNLib.Utils is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 
+* General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License 
+* along with VNLib.Utils. If not, see http://www.gnu.org/licenses/.
+*/
+
+using System;
+using System.Runtime.InteropServices;
+
+namespace VNLib.Utils
+{
+    /// <summary>
+    /// Implements a C style integer error code type. Size is platform dependent
+    /// </summary>
+    [StructLayout(LayoutKind.Sequential)]
+    public readonly struct ERRNO : IEquatable<ERRNO>, ISpanFormattable, IFormattable
+    {
+        /// <summary>
+        /// Represents a successfull error code (true)
+        /// </summary>
+        public static readonly ERRNO SUCCESS = true;
+
+        /// <summary>
+        /// Represents a failure error code (false)
+        /// </summary>
+        public static readonly ERRNO E_FAIL = false;
+        
+        private readonly nint ErrorCode;
+        /// <summary>
+        /// Creates a new <see cref="ERRNO"/> from the specified error value
+        /// </summary>
+        /// <param name="errno">The value of the error to represent</param>
+        public ERRNO(nint errno) => ErrorCode = errno;
+        /// <summary>
+        /// Creates a new <see cref="ERRNO"/> from an <see cref="int"/> error code. null = 0 = false
+        /// </summary>
+        /// <param name="errorVal">Error code</param>
+        public static implicit operator ERRNO(int errorVal) => new (errorVal);
+        /// <summary>
+        /// Creates a new <see cref="ERRNO"/> from an <see cref="int"/> error code. null = 0 = false
+        /// </summary>
+        /// <param name="errorVal">Error code</param>
+        public static explicit operator ERRNO(int? errorVal) => new(errorVal ?? 0);
+        /// <summary>
+        /// Creates a new <see cref="ERRNO"/> from a booleam, 1 if true, 0 if false
+        /// </summary>
+        /// <param name="errorVal"></param>
+        public static implicit operator ERRNO(bool errorVal) => new(errorVal ? 1 : 0);
+        /// <summary>
+        /// Creates a new <see cref="ERRNO"/> from a pointer value
+        /// </summary>
+        /// <param name="errno">The pointer value representing an error code</param>
+        public static implicit operator ERRNO(nint errno) => new(errno);
+        /// <summary>
+        /// Error value as integer. Value of supplied error code or if cast from boolean 1 if true, 0 if false
+        /// </summary>
+        /// <param name="errorVal"><see cref="ERRNO"/> to get error code from</param>
+        public static implicit operator int(ERRNO errorVal) => (int)errorVal.ErrorCode;
+        /// <summary>
+        /// C style boolean conversion. false if 0, true otherwise 
+        /// </summary>
+        /// <param name="errorVal"></param>
+        public static implicit operator bool(ERRNO errorVal) => errorVal != 0;       
+        /// <summary>
+        /// Creates a new <see cref="IntPtr"/> from the value if the stored (nint) error code 
+        /// </summary>
+        /// <param name="errno">The <see cref="ERRNO"/> contating the pointer value</param>
+        public static implicit operator IntPtr(ERRNO errno) => new(errno.ErrorCode);
+        /// <summary>
+        /// Creates a new <c>nint</c> from the value if the stored error code 
+        /// </summary>
+        /// <param name="errno">The <see cref="ERRNO"/> contating the pointer value</param>
+        public static implicit operator nint(ERRNO errno) => errno.ErrorCode;
+
+        public static ERRNO operator +(ERRNO err, int add) => new(err.ErrorCode + add);
+        public static ERRNO operator +(ERRNO err, nint add) => new(err.ErrorCode + add);
+        public static ERRNO operator ++(ERRNO err) => new(err.ErrorCode + 1);
+        public static ERRNO operator --(ERRNO err) => new(err.ErrorCode - 1);
+        public static ERRNO operator -(ERRNO err, int subtract) => new(err.ErrorCode - subtract);
+        public static ERRNO operator -(ERRNO err, nint subtract) => new(err.ErrorCode - subtract);
+
+        public static bool operator >(ERRNO err, ERRNO other) => err.ErrorCode > other.ErrorCode;
+        public static bool operator <(ERRNO err, ERRNO other) => err.ErrorCode < other.ErrorCode;
+        public static bool operator >=(ERRNO err, ERRNO other) => err.ErrorCode >= other.ErrorCode;
+        public static bool operator <=(ERRNO err, ERRNO other) => err.ErrorCode <= other.ErrorCode;
+
+        public static bool operator >(ERRNO err, int other) => err.ErrorCode > other;
+        public static bool operator <(ERRNO err, int other) => err.ErrorCode < other;
+        public static bool operator >=(ERRNO err, int other) => err.ErrorCode >= other;
+        public static bool operator <=(ERRNO err, int other) => err.ErrorCode <= other;
+
+        public static bool operator >(ERRNO err, nint other) => err.ErrorCode > other;
+        public static bool operator <(ERRNO err, nint other) => err.ErrorCode < other;
+        public static bool operator >=(ERRNO err, nint other) => err.ErrorCode >= other;
+        public static bool operator <=(ERRNO err, nint other) => err.ErrorCode <= other;
+
+        public static bool operator ==(ERRNO err, ERRNO other) => err.ErrorCode == other.ErrorCode;
+        public static bool operator !=(ERRNO err, ERRNO other) => err.ErrorCode != other.ErrorCode;
+        public static bool operator ==(ERRNO err, int other) => err.ErrorCode == other;
+        public static bool operator !=(ERRNO err, int other) => err.ErrorCode != other;
+        public static bool operator ==(ERRNO err, nint other) => err.ErrorCode == other;
+        public static bool operator !=(ERRNO err, nint other) => err.ErrorCode != other;
+
+        public readonly bool Equals(ERRNO other) => ErrorCode == other.ErrorCode;
+        public readonly override bool Equals(object obj) => obj is ERRNO other && Equals(other);
+        public readonly override int GetHashCode() => ErrorCode.GetHashCode();
+
+        /// <summary>
+        /// The integer error value of the current instance in radix 10
+        /// </summary>
+        /// <returns></returns>
+        public readonly override string ToString()
+        {
+            //Return the string of the error code number
+            return ErrorCode.ToString();
+        }
+        public readonly string ToString(string format)
+        {
+            //Return the string of the error code number
+            return ErrorCode.ToString(format);
+        }
+
+        ///<inheritdoc/>
+        public readonly bool TryFormat(Span<char> destination, out int charsWritten, ReadOnlySpan<char> format, IFormatProvider provider)
+        {
+            return ErrorCode.TryFormat(destination, out charsWritten, format, provider);
+        }
+        ///<inheritdoc/>
+        public readonly string ToString(string format, IFormatProvider formatProvider)
+        {
+            return ErrorCode.ToString(format, formatProvider);
+        }
+    }
+}