From b0e3019fb301362dedd376ba3f4fb7263b277c11 Mon Sep 17 00:00:00 2001
From: erikmchut <mc@8thwall.com>
Date: Wed, 13 May 2020 11:49:41 -0700
Subject: [PATCH] Remove std::optional entirely for compatibility on older
 toolchains.

---
 src/mp4.cpp     |  6 +++---
 src/mp4file.cpp | 19 ++++++++-----------
 src/mp4file.h   |  4 +---
 3 files changed, 12 insertions(+), 17 deletions(-)

diff --git a/src/mp4.cpp b/src/mp4.cpp
index 42fb8dd..70b2145 100644
--- a/src/mp4.cpp
+++ b/src/mp4.cpp
@@ -2236,9 +2236,9 @@ MP4FileHandle MP4ReadProvider( const char* fileName, const MP4FileProvider* file
         MP4FileHandle hFile, MP4TrackId trackId)
     {
         if (MP4_IS_VALID_FILE_HANDLE(hFile)) {
-          auto index = ((MP4File*)hFile)->MaybeFindTrackIndex(trackId);
-          if (index.has_value()) {
-            return index.value();
+          MP4File* phFile = reinterpret_cast<MP4File*>(hFile);
+          if (phFile->TrackIndexExists(trackId)) {
+            return phFile->FindTrackIndex(trackId);
           }
           mp4v2::impl::log.errorf( "%s: failed", __FUNCTION__ );
         }
diff --git a/src/mp4file.cpp b/src/mp4file.cpp
index 8cba2e8..a77fa21 100644
--- a/src/mp4file.cpp
+++ b/src/mp4file.cpp
@@ -2857,8 +2857,7 @@ MP4TrackId MP4File::AllocTrackId()
 
     if (trackId <= 0xFFFF) {
         // check that nextTrackid is correct
-        auto index = MaybeFindTrackIndex(trackId);
-        if (!index.has_value()) {
+        if (!TrackIndexExists(trackId)) {
             // OK, this trackId is not in use, proceed
             SetIntegerProperty("moov.mvhd.nextTrackId", trackId + 1);
             return trackId;
@@ -2867,8 +2866,7 @@ MP4TrackId MP4File::AllocTrackId()
 
     // we need to search for a track id
     for (trackId = 1; trackId <= 0xFFFF; trackId++) {
-        auto index = MaybeFindTrackIndex(trackId);
-        if (!index.has_value()) {
+        if (!TrackIndexExists(trackId)) {
             // OK, this trackId is not in use, proceed
             return trackId;
         }
@@ -2932,14 +2930,13 @@ uint16_t MP4File::FindTrackIndex(MP4TrackId trackId)
     return (uint16_t)-1; // satisfy MS compiler
 }
 
-std::optional<uint16_t> MP4File::MaybeFindTrackIndex(MP4TrackId trackId)
-{
-    for (uint32_t i = 0; i < m_pTracks.Size() && i <= 0xFFFF; i++) {
-        if (m_pTracks[i]->GetId() == trackId) {
-            return (uint16_t)i;
-        }
+bool MP4File::TrackIndexExists(MP4TrackId trackId) {
+  for (uint32_t i = 0; i < m_pTracks.Size() && i <= 0xFFFF; i++) {
+    if (m_pTracks[i]->GetId() == trackId) {
+      return true;
     }
-    return {};
+  }
+  return false;
 }
 
 uint16_t MP4File::FindTrakAtomIndex(MP4TrackId trackId)
diff --git a/src/mp4file.h b/src/mp4file.h
index 45686c3..9a62d42 100644
--- a/src/mp4file.h
+++ b/src/mp4file.h
@@ -33,8 +33,6 @@
 #ifndef MP4V2_IMPL_MP4FILE_H
 #define MP4V2_IMPL_MP4FILE_H
 
-#include <optional>
-
 namespace mp4v2 { namespace impl {
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -148,7 +146,7 @@ class MP4File
     MP4TrackId FindTrackId(uint16_t trackIndex,
                            const char* type = NULL, uint8_t subType = 0);
     uint16_t FindTrackIndex(MP4TrackId trackId);
-    std::optional<uint16_t> MaybeFindTrackIndex(MP4TrackId trackId);
+    bool TrackIndexExists(MP4TrackId trackId);
     uint16_t FindTrakAtomIndex(MP4TrackId trackId);
 
     /* track properties */