Reduce unnecessary COW on Vector by make writing explicit

This commit makes operator[] on Vector const and adds a write proxy to it.  From
now on writes to Vectors need to happen through the .write proxy. So for
instance:

Vector<int> vec;
vec.push_back(10);
std::cout << vec[0] << std::endl;
vec.write[0] = 20;

Failing to use the .write proxy will cause a compilation error.

In addition COWable datatypes can now embed a CowData pointer to their data.
This means that String, CharString, and VMap no longer use or derive from
Vector.

_ALWAYS_INLINE_ and _FORCE_INLINE_ are now equivalent for debug and non-debug
builds. This is a lot faster for Vector in the editor and while running tests.
The reason why this difference used to exist is because force-inlined methods
used to give a bad debugging experience. After extensive testing with modern
compilers this is no longer the case.

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/gles2/shader_gles2.cpp b/drivers/gles2/shader_gles2.cpp
index fa9562877d..baada9331e 100644
--- a/drivers/gles2/shader_gles2.cpp
+++ b/drivers/gles2/shader_gles2.cpp
@@ -288,7 +288,7 @@ ShaderGLES2::Version *ShaderGLES2::get_current_version() {
 
 	if (cc) {
 		for (int i = 0; i < cc->custom_defines.size(); i++) {
-			strings.push_back(cc->custom_defines[i]);
+			strings.push_back(cc->custom_defines.write[i]);
 			DEBUG_PRINT("CD #" + itos(i) + ": " + String(cc->custom_defines[i]));
 		}
 	}
@@ -502,7 +502,7 @@ ShaderGLES2::Version *ShaderGLES2::get_current_version() {
 	if (cc) {
 		v.custom_uniform_locations.resize(cc->custom_uniforms.size());
 		for (int i = 0; i < cc->custom_uniforms.size(); i++) {
-			v.custom_uniform_locations[i] = glGetUniformLocation(v.id, String(cc->custom_uniforms[i]).ascii().get_data());
+			v.custom_uniform_locations.write[i] = glGetUniformLocation(v.id, String(cc->custom_uniforms[i]).ascii().get_data());
 		}
 	}