Finish converting GSL to absl::Span

One less dependency.

Change-Id: Iaac25a3c1312a21a8a2b77b8cfee2463bdb51196
Signed-off-by: Austin Schuh <austin.linux@gmail.com>
diff --git a/y2019/jevois/cobs.h b/y2019/jevois/cobs.h
index b8a6e4b..979cc15 100644
--- a/y2019/jevois/cobs.h
+++ b/y2019/jevois/cobs.h
@@ -36,7 +36,7 @@
 // output buffer is exhausted and return the result.
 template <size_t max_decoded_size>
 absl::Span<char> CobsDecode(absl::Span<const char> input,
-                           std::array<char, max_decoded_size> *output_buffer);
+                            std::array<char, max_decoded_size> *output_buffer);
 
 // Manages scanning a stream of bytes for 0s and exposing the resulting buffers.
 //
@@ -134,7 +134,7 @@
 
 template <size_t max_decoded_size>
 absl::Span<char> CobsDecode(absl::Span<const char> input,
-                           std::array<char, max_decoded_size> *output_buffer) {
+                            std::array<char, max_decoded_size> *output_buffer) {
   static_assert(max_decoded_size > 0, "Empty buffers not supported");
   if (static_cast<size_t>(input.size()) >
       CobsMaxEncodedSize(max_decoded_size)) {
diff --git a/y2019/jevois/teensy.cc b/y2019/jevois/teensy.cc
index 541fabe..95fe186 100644
--- a/y2019/jevois/teensy.cc
+++ b/y2019/jevois/teensy.cc
@@ -2,6 +2,7 @@
 #include <cstdio>
 #include <optional>
 
+#include "absl/types/span.h"
 #include "aos/time/time.h"
 #include "motors/core/kinetis.h"
 #include "motors/core/time.h"
@@ -10,7 +11,6 @@
 #include "motors/peripheral/uart.h"
 #include "motors/print/print.h"
 #include "motors/util.h"
-#include "third_party/GSL/include/gsl/gsl"
 #include "y2019/jevois/cobs.h"
 #include "y2019/jevois/spi.h"
 #include "y2019/jevois/uart.h"
@@ -152,8 +152,9 @@
         all_done = to_receive_.empty();
       } else {
         std::array<char, 1> dummy_data;
-        if (global_spi_instance->Read(dummy_data, &disable_interrupts).size() >=
-            1) {
+        if (global_spi_instance
+                ->Read(absl::Span<char>(dummy_data), &disable_interrupts)
+                .size() >= 1) {
           received_dummy_ = true;
         }
         all_done = false;
@@ -453,40 +454,40 @@
   while (true) {
     {
       std::array<char, 10> buffer;
-      const auto data = uarts->cam0.Read(buffer);
-      for (int i = 0; i < data.size(); ++i) {
+      const auto data = uarts->cam0.Read(absl::Span<char>(buffer));
+      for (size_t i = 0; i < data.size(); ++i) {
         data[i] += 1;
       }
       uarts->cam0.Write(data);
     }
     {
       std::array<char, 10> buffer;
-      const auto data = uarts->cam1.Read(buffer);
-      for (int i = 0; i < data.size(); ++i) {
+      const auto data = uarts->cam1.Read(absl::Span<char>(buffer));
+      for (size_t i = 0; i < data.size(); ++i) {
         data[i] += 2;
       }
       uarts->cam1.Write(data);
     }
     {
       std::array<char, 10> buffer;
-      const auto data = uarts->cam2.Read(buffer);
-      for (int i = 0; i < data.size(); ++i) {
+      const auto data = uarts->cam2.Read(absl::Span<char>(buffer));
+      for (size_t i = 0; i < data.size(); ++i) {
         data[i] += 3;
       }
       uarts->cam2.Write(data);
     }
     {
       std::array<char, 10> buffer;
-      const auto data = uarts->cam3.Read(buffer);
-      for (int i = 0; i < data.size(); ++i) {
+      const auto data = uarts->cam3.Read(absl::Span<char>(buffer));
+      for (size_t i = 0; i < data.size(); ++i) {
         data[i] += 4;
       }
       uarts->cam3.Write(data);
     }
     {
       std::array<char, 10> buffer;
-      const auto data = uarts->cam4.Read(buffer);
-      for (int i = 0; i < data.size(); ++i) {
+      const auto data = uarts->cam4.Read(absl::Span<char>(buffer));
+      for (size_t i = 0; i < data.size(); ++i) {
         data[i] += 5;
       }
       uarts->cam4.Write(data);
@@ -673,11 +674,11 @@
 
     {
       std::array<char, 20> buffer;
-      packetizers[0].ParseData(uarts->cam0.Read(buffer));
-      packetizers[1].ParseData(uarts->cam1.Read(buffer));
-      packetizers[2].ParseData(uarts->cam2.Read(buffer));
-      packetizers[3].ParseData(uarts->cam3.Read(buffer));
-      packetizers[4].ParseData(uarts->cam4.Read(buffer));
+      packetizers[0].ParseData(uarts->cam0.Read(absl::Span<char>(buffer)));
+      packetizers[1].ParseData(uarts->cam1.Read(absl::Span<char>(buffer)));
+      packetizers[2].ParseData(uarts->cam2.Read(absl::Span<char>(buffer)));
+      packetizers[3].ParseData(uarts->cam3.Read(absl::Span<char>(buffer)));
+      packetizers[4].ParseData(uarts->cam4.Read(absl::Span<char>(buffer)));
     }
     for (size_t i = 0; i < packetizers.size(); ++i) {
       if (!packetizers[i].received_packet().empty()) {
diff --git a/y2019/jevois/uart.cc b/y2019/jevois/uart.cc
index 71c37e5..2857bd6 100644
--- a/y2019/jevois/uart.cc
+++ b/y2019/jevois/uart.cc
@@ -2,8 +2,8 @@
 
 #include <array>
 
-#include "aos/util/bitpacking.h"
 #include "absl/types/span.h"
+#include "aos/util/bitpacking.h"
 #include "y2019/jevois/jevois_crc.h"
 #ifdef __linux__
 #include "aos/logging/logging.h"